Advertisement

Vascular reactions in children

      Urticaria

      It has been estimated that 10–20% of the general population experiences an episode of urticaria during their lifetime.
      • Twarog F.J.
      Urticaria in childhood pathogenesis and management.
      Urticaria is a common disease of childhood, and the incidence in children is reported to range between 2.4% and 8.3%.
      • Mortureux P.
      • Leaute-Labreze C.
      • Legrain-Lifermanna V.
      • et al.
      Acute urticaria in infancy and early childhood.
      Chronic urticaria, defined arbitrarily as lesions present for longer than 6 weeks, develops in a variable proportion of patients ranging, from 5% to 30%. Between 42% and 50% of children with chronic urticaria continue to have symptoms for > 1 year. Within the chronic category, it is suggested that children under the age of 8 years have a higher resolution rate.
      • Twarog F.J.
      Urticaria in childhood pathogenesis and management.
      ,
      • Mortureux P.
      • Leaute-Labreze C.
      • Legrain-Lifermanna V.
      • et al.
      Acute urticaria in infancy and early childhood.

      Clinical picture

      Urticarial lesions may involve any area of the body. Wheals assume variable sizes and shapes and oftentimes have raised erythematous, serpiginous edges and blanched centers (Fig 1). In the young child, hemorrhagic patterns are not infrequent. Characteristically, the lesions are intensely pruritic and evanescent. Angioedema, a similar process occurring in deeper dermal and subcutaneous layers, appears on the face and extremities. Pruritis may or may not be present.
      • Mortureux P.
      • Leaute-Labreze C.
      • Legrain-Lifermanna V.
      • et al.
      Acute urticaria in infancy and early childhood.
      Figure thumbnail GR1
      Figure 1Urticarial lesions; legs.

      Etiology-pathogenesis

      Urticaria is a type I hypersensitivity reaction and involves mast cell degranulation. Stimulation of mast cell mediator release may result from both immune- and nonimmune-mediated mechanisms. Perhaps the most clinically relevant of these mechanisms is the cross-linkage of high-affinity immunoglobulin E (IgE) receptors (FcϵRI) on mast cells by antigen-specific IgE.
      • Eady R.
      • Cowen T.
      • Marshall T.
      • et al.
      Mast cell population density, blood vessel density and histamine content in normal human skin.
      ,
      • Wiesner-Menzel L.
      • Schula B.
      • Vakilzadeh F.
      • et al.
      Electronic microscopic evidence for a direct contact between nerve fibers and mast cells.
      ,
      • Sabroe R.
      • Greaves M.
      The pathogenesis of chronic idiopathic urticaria.
      ,
      • Tharp M.D.
      The mast cell.
      ,
      • Jorizzo J.
      Urticaria.
      ,
      • Tharp M.D.
      • Kagey-Sabotka A.
      • Fox C.C.
      • et al.
      Functional heterogeneity of human mast cells from different anatomical sites in vitro responses to morphine sulfate.
      It has been shown that a category of chronic idiopathic urticaria is associated with circulating, functional, histamine-releasing auto-antibodies that bind to IgE receptors (FcϵRI) or, less frequently, to IgE.
      • Hide M.
      • Francis D.M.
      • Grattan C.
      • et al.
      Autoantibodies against the high affinity IgE receptor as a cause of histamine release in chronic urticaria.
      In addition to histamine, mast cell mediators include prostaglandin D2, proteases, and various cytokines.
      • Sabroe R.
      • Greaves M.
      The pathogenesis of chronic idiopathic urticaria.
      ,
      • Weston W.L.
      • Badgett J.T.
      Urticaria.
      Urticaria can be caused by a wide variety of factors.
      • Twarog F.J.
      Urticaria in childhood pathogenesis and management.
      Success in identifying a cause in childhood urticaria is variable and ranges between 21% and 83%. The acute form of urticaria appears to occur more often in the atopic population, and the likelihood that the underlying cause can be identified is significant. In contrast, the cause of chronic urticaria is identified < 3% of the time.
      • Twarog F.J.
      Urticaria in childhood pathogenesis and management.
      ,
      • Jorizzo J.
      Urticaria.
      ,
      • Ghosh S.
      • Kanwar A.J.
      • Kaur S.
      Urticaria in children.
      In children, various acute, benign infections, including viral illnesses, frequently trigger urticaria. In such instances, drug therapy has been instituted, making it difficult to distinguish between these two triggering factors. Food allergy is yet another common cause of acute, recurrent urticaria in childhood. The frequency ranges between 11% and 62%.
      • Twarog F.J.
      Urticaria in childhood pathogenesis and management.
      ,
      • Mortureux P.
      • Leaute-Labreze C.
      • Legrain-Lifermanna V.
      • et al.
      Acute urticaria in infancy and early childhood.
      ,
      • Kamppinen K.
      • Juntunen K.
      • Lanki H.
      Urticaria in children retrospective evaluation and follow-up.
      ,
      • Kobza Black A.
      Urticarial vasculitis.
      Sensitivity to eggs and, less often, milk is common during the first year of life. This sensitivity is lost during early childhood. In young children, peanuts, nuts, and berries are often implicated, while shellfish and fish sensitivity usually does not occur until later.
      • Twarog F.J.
      Urticaria in childhood pathogenesis and management.

      Treatment

      If a cause is identified, avoidance of the causative agent or addressing the associated disease is indicated. Antihistamines of the H1 class (sedating/nonsedating) remain the treatment of choice, usually providing symptomatic control.
      • Twarog F.J.
      Urticaria in childhood pathogenesis and management.
      ,
      • Jorizzo J.
      Urticaria.
      It is unclear whether the addition of histamine-2-blocking drugs to H-1 antihistamines is of any additional benefit.
      • Weston W.L.
      • Badgett J.T.
      Urticaria.
      Although systemic corticosteroids are rarely indicated, a brief course may be necessary to control severe, acute reactions.
      • Twarog F.J.
      Urticaria in childhood pathogenesis and management.
      In acute angioedema in which airways are affected, epinephrine may be life-saving. Cromolyn sodium preparations have not been useful in urticaria.
      • Weston W.L.
      • Badgett J.T.
      Urticaria.
      Ketotifen may be useful in chronic urticaria, and photochemotherapy may be considered.
      • Weston W.L.
      • Badgett J.T.
      Urticaria.
      ,
      • Egan C.A.
      • Rallis T.M.
      Treatment of chronic urticaria with ketotifen.
      With evidence incriminating circulating autoantibodies against IgE receptors in chronic forms of urticaria, new treatment modalities have been introduced. These include immunosuppressive drugs such as cyclosporine and intravenous immunoglobulins. Additionally, leukotriene inhibitors have been assessed and may be beneficial.
      • Sabroe R.
      • Greaves M.
      The pathogenesis of chronic idiopathic urticaria.
      ,
      • Weston W.L.
      • Morelli J.G.
      Herpes simplex virus-associated erythema multiforme in prepubertal children.

      Erythema multiforme

      The clinical spectrum of erythema multiforme (EM) includes two different presentations. The mild, mainly cutaneous process, originally described by Von Hebra, is known as EM minor, and a more serious mucocutaneous disease described by Stevens and Johnson is known as EM major.
      • Brice S.L.
      • Huff J.C.
      • Weston W.L.
      Erythema multiforme.

      Clinical picture

      EM minor is an acute, self-limited mucocutaneous eruption, generally occurring without a prodrome. The onset of skin lesions is abrupt, with virtually all lesions appearing within the first 72 hours of the illness. Young adults aged 20–40 years are most likely to suffer, although children and rarely, infants are affected.
      • Weston W.L.
      • Morelli J.G.
      Herpes simplex virus-associated erythema multiforme in prepubertal children.
      ,
      • de Ocariz M.
      • Vega-Memije E.
      • Munoz-Hink H.
      A case of herpetic whitlow associated with erythema multiforme.
      The majority of children are preadolescents or adolescents, in whom the course and evolution of lesions are the same as those observed in young adults.
      • Edmond B.J.
      • Huff J.C.
      • Weston W.L.
      Erythema multiforme.
      Lesions include symmetrically distributed, fixed red macules, papules, and plaques, with the upper extremities being mostly affected (Fig 2). Generally, the erythematous border of the papule expands and the central zone becomes dusky in color, producing the distinctive “target” or “iris” lesion. Involvement of the oral mucosa sometimes occurs.
      • Brice S.L.
      • Huff J.C.
      • Weston W.L.
      Erythema multiforme.
      ,
      • Edmond B.J.
      • Huff J.C.
      • Weston W.L.
      Erythema multiforme.
      ,
      • Huff J.C.
      • Weston W.L.
      • Tonnesen M.G.
      Erythema multiforme a critical review of characteristics, diagnostic criteria and causes.
      The development of lesions at sites of trauma (isomorphic phenomenon) has been described.
      • Huff J.C.
      • Weston W.L.
      Isomorphic phenomenon in erythema multiforme.
      Symptoms include itching, burning, and prickling sensations. The duration of EM minor ranges between 1 and 4 weeks, with a median duration of 2–3 weeks. Patients are febrile and lymphadenopathy is usually absent, except when oral lesions are present.
      • Brice S.L.
      • Huff J.C.
      • Weston W.L.
      Erythema multiforme.
      Figure thumbnail GR2
      Figure 2Erythema multiforme (including target lesions).

      Etiology-pathogenesis

      The best-documented precipitating factor of EM minor is an antecedent infection with herpes simplex virus (HSV). The EM lesions typically develop from 3 to 21 days after herpes infection. Recurrent EM minor does not necessarily follow each episode of recurrent HSV, nor does a clinically apparent HSV infection always antedate EM minor.
      • Forman L.
      • Whitwell C.P.B.
      The association of herpes catarrhalis with erythema multiforme.
      ,
      • Leigh I.M.
      • Mowbray J.F.
      • Levene J.M.
      • et al.
      Recurrent and continuous erythema multiforme a clinical and immunological study.
      ,
      • Huff J.C.
      • Weston W.L.
      Recurrent erythema multiforme.
      ,
      • Brice S.L.
      • Krzemien D.
      • Weston W.L.
      • et al.
      Detection of herpes simplex virus DNA in cutaneous lesions of erythema multiforme.
      Immunohistochemical studies have shown that the inflammatory infiltrate is predominantly composed of T lymphocytes, of helper and suppressor subsets. These findings, together with the histological evidence that the keratinocyte is a primary target of inflammatory injury, support a cell-mediated immune response directed against HSV antigens within the epidermis. Genetic differences in the host response to HSV might explain why only certain patients who suffer from HSV infection develop EM minor.
      • Brice S.L.
      • Krzemien D.
      • Weston W.L.
      • et al.
      Detection of herpes simplex virus DNA in cutaneous lesions of erythema multiforme.
      ,
      • Schofield J.K.
      • Tatnall F.M.
      • Brown J.
      • et al.
      Recurrent erythema multiforme tissue typing in a large series of patients.

      Management

      Systemic steroids are commonly used in the treatment of EM minor, despite the lack of objective evidence supporting their value in the treatment of this disease.
      • Huff J.C.
      • Weston W.L.
      • Tonnesen M.G.
      Erythema multiforme a critical review of characteristics, diagnostic criteria and causes.
      ,
      • Leigh I.M.
      • Mowbray J.F.
      • Levene J.M.
      • et al.
      Recurrent and continuous erythema multiforme a clinical and immunological study.
      ,
      • Huff J.C.
      • Weston W.L.
      Recurrent erythema multiforme.
      It is likely that by the time the patient seeks medical attention, much of the immunological tissue damage will have already occurred.
      • Renfro L.
      • Grant-Kels J.M.
      • Feder H.M.
      • et al.
      Controversy are systemic steroids indicated in the treatment of erythema multiforme?.
      Suppression of the host response might permit HSV replication to go unchecked, resulting in continuous, overlapping episodes of EM minor.
      • Leigh I.M.
      • Mowbray J.F.
      • Levene J.M.
      • et al.
      Recurrent and continuous erythema multiforme a clinical and immunological study.
      ,
      • Huff J.C.
      • Weston W.L.
      Recurrent erythema multiforme.
      Discontinuing suspected medications and dealing with possible infections are needed. Oral antihistamines to relieve itching and burning sensations as well as anti-herpesvirus medications such as acyclovir are helpful. Acyclovir is best used for prophylaxis in patients with recurrent EM minor.
      • Brice S.L.
      • Huff J.C.
      • Weston W.L.
      Erythema multiforme.

      Stevens-Johnson syndrome (erythema mutliforme major)—toxic epidermal necrolysis

      There is growing evidence that Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) constitute a spectrum of disease process distinct from erythema multiforme minor.
      • Garcia-Doval I.
      • Le Cleach L.
      • Bouquet H.
      • et al.
      Toxic epidermal necrolysis and Stevens-Johnson syndrome — does early withdrawal of causative drugs decrease the risk of death?.
      SJS is a serious mucocutaneous illness in which lesions involving at least two mucosal sites, in addition to skin lesions that evolve into bullae and extensive areas of epidermal necrosis and separation, develop. SJS occurs at any age, with the main peak in the second decade and a smaller peak in the fifth decade.
      • Brice S.L.
      • Huff J.C.
      • Weston W.L.
      Erythema multiforme.
      In some series, the majority of patients were children.
      • Ting H.C.
      • Adam B.A.
      Stevens-Johnson syndrome a review of 34 cases.
      ,
      • Ruiz-Maldonado R.
      Acute disseminated epidermal necrosis types 1, 2 and 3 study of sixty cases.

      Clinical features

      A prodrome lasting from one to several days with fever, headache, malaise, sore throat, vomiting, and diarrhea present in > 50% of patients. Skin lesions appear as in EM minor; however, there is rapid evolution to involve large areas with bulla formation, epidermal necrosis, and separation. Nickolsky sign is positive. On top of the oral mucosa, the conjunctiva and genitalia may be involved. In up to 39% of patients, all three mucosal surfaces are affected.
      • Brice S.L.
      • Huff J.C.
      • Weston W.L.
      Erythema multiforme.
      ,
      • Ting H.C.
      • Adam B.A.
      Stevens-Johnson syndrome a review of 34 cases.
      ,
      • Ruiz-Maldonado R.
      Acute disseminated epidermal necrosis types 1, 2 and 3 study of sixty cases.
      Characteristically patients develop hemorrhagic crusts on the lips that evolve into a pseudomembrane of necrotic epithelium and inflammatory cells. More severe involvement of the oral mucosa may interfere with eating, swallowing, and talking. When the eyes are involved, redness, erosions, and purulent exudate may be present.
      • Brice S.L.
      • Huff J.C.
      • Weston W.L.
      Erythema multiforme.
      Damage to the respiratory mucosa with persistent cough and pleural effusion may be seen. Injury to the gastrointestinal tract results in dysphasia, abdominal pain, diarrhea, and melena.
      • Brice S.L.
      • Huff J.C.
      • Weston W.L.
      Erythema multiforme.
      Patients with this illness have been classified according to the extent of detached/detachable epidermis. If it is < 10%, SJS is used; those with cutaneous detachment of 10–30% are called transitional SJS-TEN patients; and those with more than 30%, are designated TEN patients (Fig 3). In general, patients with SJS and SJS-TEN have better prognosis than do those with TEN.
      • Garcia-Doval I.
      • Le Cleach L.
      • Bouquet H.
      • et al.
      Toxic epidermal necrolysis and Stevens-Johnson syndrome — does early withdrawal of causative drugs decrease the risk of death?.
      Figure thumbnail GR3
      Figure 3Toxic epidermal necrolysis.

      Etiology-pathogenesis

      Drugs are clearly the leading causative factor in SJS-TEN, mostly sulfonamides, anticonvulsants, and nonsteroidal anti-inflammatory agents.
      • Roujeau J.C.
      • Stern R.
      Severe adverse cutaneous reactions to drugs.
      The predisposing factors that may promote the development of SJS-TEN include a genetic susceptibility as well as drug interactions.
      • Roujeau J.C.
      • Kelly J.P.
      • Naldi L.
      • et al.
      Medication use and the risk of Stevens-Johnson syndrome or toxic epidermal necrolysis.
      It has been suggested that SJS-TEN is linked to a defect of the detoxification systems in the liver and skin. The disease process is viewed as a cytotoxic immune reaction aiming at destruction of keratinocyte-expressing foreign antigens related to drugs or their metabolites.
      • Shear N.H.
      • Spielberg S.P.
      • Grant D.M.
      • et al.
      Differences in metabolism of sulfonamides predisposing to idiosyncratic toxicity.
      ,
      • Kakourou T.
      • Klontza D.
      • Soteropoulou F.
      • et al.
      Corticosteroid treatment in erythema multiforme major (Stevens-Johnson syndrome) in children.

      Management

      Prompt withdrawal of suspected drugs is very essential. It was shown that early discontinuation of causative drugs (with short elimination half-lives) was associated with a better outcome. That was independent of the main known prognostic factors, age, and the extent of epidermal detachment.
      • Garcia-Doval I.
      • Le Cleach L.
      • Bouquet H.
      • et al.
      Toxic epidermal necrolysis and Stevens-Johnson syndrome — does early withdrawal of causative drugs decrease the risk of death?.
      Most authorities recommend treatment of patients in a burn unit. Careful attention to secondary infections and replacement of lost fluids, electrolytes, and calories are essential.
      • Brice S.L.
      • Huff J.C.
      • Weston W.L.
      Erythema multiforme.
      The use of systemic corticosteroids is disfavored; however, some studies report a favorable influence of an early and short course of corticosteroids in children with SJS.
      • Kakourou T.
      • Klontza D.
      • Soteropoulou F.
      • et al.
      Corticosteroid treatment in erythema multiforme major (Stevens-Johnson syndrome) in children.
      Recently, treatment of TEN by intravenous immunoglobulins rapidly reversed disease progression and the outcome was favorable. It was shown that the antibodies present in the pooled human immunoglobulins block the death receptor Fas that is normally expressed on keratinocytes. This inhibits the interaction between the Fas receptor and its respective ligand and thus, prevents apoptosis.
      • Viard I.
      • Wehrli P.
      • Bullani R.
      • et al.
      Inhibition of toxic epidermal necrolysis by blockade of CD95 with human intravenous immunoglobulin.

      Henoch-Schönlein (anaphylactoid) purpura

      Henoch-Shönlein purpura (HSP) is a form of leukocytoclastic vasculitis characterized by palpable, purpuric skin lesions, arthritis, abdominal pain, and glomerulonephritis. It is the most common form of vasculitis occurring in childhood, mainly 3–10 years of age. It represents an immunological response triggered by a multitude of drugs and infectious agents.
      • Raimer S.S.
      • Sanchez R.L.
      Vasculitis in children.

      Clinical picture

      Palpable purpura occurs in 100% of cases (Fig 4) but is the presenting sign in only 50% of patients. Hemorrhagic vesicles are uncommon. Dependent areas such as the legs and buttocks are primarily involved. Scrotal involvement is not uncommon.
      • Raimer S.S.
      • Sanchez R.L.
      Vasculitis in children.
      ,
      • Nussinovitch M.
      • Prais D.
      • Finkelstein Y.
      • et al.
      Cutaneous manifestations of Henoch-Shonlein purpura in young children.
      Edema of hands, feet, scalp, and ears may be early findings. Arthritis and arthralgias are common in HSP, affecting 60–84% of patients, with the ankles and knees primarily involved.
      • Saulsbury Ft.
      Henoch-Schonlein purpura.
      ,
      • Golitz L.E.
      The vasculitides and their significance in the pediatric age group.
      Gastrointestinal involvement occurs in up to 76% of patients. This presents as abdominal pain, nausea, vomiting, and gastrointestinal bleeding.
      • Tomomasa T.
      • Hsu J.Y.
      • Itoh K.
      • et al.
      Endoscopic findings in pediatric patients with Henoch-Schonlein purpura and gastrointestinal symptoms.
      Major hemorrhage occurs in 5% and intussusception in 3–5% of patients.
      • Saulsbury Ft.
      Henoch-Schonlein purpura.
      Renal involvement occurs in 10–50% of patients, with children older than 9 years and those with bloody stools reportedly having an increased risk.
      • Raimer S.S.
      • Sanchez R.L.
      Vasculitis in children.
      However, the overall prognosis is good, with 2–5% left with persistent renal disease.
      • Ansell B.
      • Falcini F.
      Cutaneous vasculitis in children.
      Rare complications include pancreatitis, cholecystitis, neurological involvement, and myocardial infarction.
      • Katz A.Z.
      • Gang D.W.
      A five year old girl with skin rash and abdominal pain.
      ,
      • Heng M.C.Y.
      Henoch-Schonlein purpura.
      Figure thumbnail GR4
      Figure 4Purpuric papules in Henoch-Schönlein purpura.

      Histology

      Histologically, HSP cannot be distinguished from other forms of leukocytoclastic vasculitis, although the degree of vascular damage is less. Immunofluorescence studies demonstrate the deposition of IgA in capillaries.
      • Barnhill R.L
      • Busam K.J.
      Vascular diseases.
      IgA deposits are found in 75% of specimens from involved skin and in 67% of specimens from uninvolved skin.
      • Van Hale H.M.
      • Gibson L.E.
      • Schroeter A.L.
      Henoch-Schonlein vasculitis direct immunolfluorescence study of uninvolved skin.

      Treatment

      Management of HSP is mainly supportive. The disease is self-limited, remitting after 1–2 weeks. It has a tendency, however, to recur a number of times over a period of weeks to months. Systemic corticosteroid has been used, especially when significant abdominal pain or renal involvement is present, although its effectiveness has been questioned. Older children who are more likely than younger children to develop progressive renal disease may benefit from early treatment.
      • Raimer S.S.
      • Sanchez R.L.
      Vasculitis in children.

      Acute hemorrhagic edema of infancy

      Acute hemorrhagic edema of infancy is an acute, leukocytoclastic vasculitis occurring in infants. It has some common clinical features with HSP and is considered by some authors to be a variant of that syndrome.
      • Amitai Y.
      • Gillis D.
      • Wasserman D.
      • et al.
      Henoch-Schonlein purpura in infants.
      Yet others regard it as a distinct clinical entity.
      • Gonggryp L.A.
      • Todd G.
      Acute hemorrhagic edema of childhood (AHE).

      Clinical picture

      Acute Hemorrhagic Edema of Infancy occurs between the ages of 4 months and 2 years. It appears usually in winter, with an acute onset of echymotic plaques and inflammatory edema. The purpuric plaques often show a cockade or targetlike morphology. The ears, cheeks, and extremities are commonly affected (Fig 5).
      • Gonggryp L.A.
      • Todd G.
      Acute hemorrhagic edema of childhood (AHE).
      ,
      • Krause I.
      • Lazarov A.
      • Rachmel A.
      • et al.
      Acute hemorrhagic edema of infancy, a benign variant of leukocytoclastic vasculitis.
      The condition is believed to represent an immune complex-mediated disease triggered by respiratory infection, drugs, streptococci, staphylococci, adenoviruses, and possibly, mycobacteria. The clinical differential diagnosis may include EM minor, child abuse, and Sweet syndrome.
      • Gonggryp L.A.
      • Todd G.
      Acute hemorrhagic edema of childhood (AHE).
      ,
      • Legrain V.
      • Lejean S.
      • Taieb A.
      • et al.
      Infantile acute hemorrrhagic edema of the skin study of ten cases.
      Figure thumbnail GR5
      Figure 5Echymotic plaques in acute hemorrhagic edema of infancy.

      Treatment

      The prognosis of Acute Hemorrhagic Edema of Infancy is excellent, with resolution occurring in 1–3 weeks. Visceral involvement is rare in contrast to HSP.
      • Gonggryp L.A.
      • Todd G.
      Acute hemorrhagic edema of childhood (AHE).
      ,
      • Legrain V.
      • Lejean S.
      • Taieb A.
      • et al.
      Infantile acute hemorrrhagic edema of the skin study of ten cases.
      [
      • O’Donnell B.F.
      • Barr R.M.
      • Kobza Black A.
      • et al.
      Intravenous immunoglobulin in autoimmune chronic urticaria.
      ]

      References

        • Twarog F.J.
        Urticaria in childhood.
        Pediatr Clin North Am. 1983; 30: 887-898
        • Mortureux P.
        • Leaute-Labreze C.
        • Legrain-Lifermanna V.
        • et al.
        Acute urticaria in infancy and early childhood.
        Arch Dermatol. 1998; 134: 319-323
        • Eady R.
        • Cowen T.
        • Marshall T.
        • et al.
        Mast cell population density, blood vessel density and histamine content in normal human skin.
        Br J Dermatol. 1979; 100: 623-633
        • Wiesner-Menzel L.
        • Schula B.
        • Vakilzadeh F.
        • et al.
        Electronic microscopic evidence for a direct contact between nerve fibers and mast cells.
        Acta Derm Venereol. 1998; 61: 465-469
        • Sabroe R.
        • Greaves M.
        The pathogenesis of chronic idiopathic urticaria.
        Arch Dermatol. 1997; 133: 1003-1008
        • Tharp M.D.
        The mast cell.
        in: Jordan R.E. Immunologic diseases of the skin. Appleton and Lange Co, Norwalk1991: 63-71
        • Jorizzo J.
        Urticaria.
        Curr Prob Dermatol. 2000; 12: 9-10
        • Tharp M.D.
        • Kagey-Sabotka A.
        • Fox C.C.
        • et al.
        Functional heterogeneity of human mast cells from different anatomical sites.
        J Allergy Clin Immunol. 1987; 79: 646-653
        • Hide M.
        • Francis D.M.
        • Grattan C.
        • et al.
        Autoantibodies against the high affinity IgE receptor as a cause of histamine release in chronic urticaria.
        N Engl J Med. 1993; 328: 1599-1604
        • Weston W.L.
        • Badgett J.T.
        Urticaria.
        Pediatr Rev. 1998; 19: 240-244
        • Ghosh S.
        • Kanwar A.J.
        • Kaur S.
        Urticaria in children.
        Pediatr Dermatol. 1993; 10: 107-110
        • Kamppinen K.
        • Juntunen K.
        • Lanki H.
        Urticaria in children.
        Allergy. 1984; 39: 469-472
        • Kobza Black A.
        Urticarial vasculitis.
        Clin Dermatol. 1999; 17: 565-569
        • Egan C.A.
        • Rallis T.M.
        Treatment of chronic urticaria with ketotifen.
        Arch Dermatol. 1997; 133: 147-149
        • O’Donnell B.F.
        • Barr R.M.
        • Kobza Black A.
        • et al.
        Intravenous immunoglobulin in autoimmune chronic urticaria.
        Br J Dermatol. 1998; 138: 101-106
        • Brice S.L.
        • Huff J.C.
        • Weston W.L.
        Erythema multiforme.
        Curr Prob Dermatol. 1990; 2: 5-25
        • Weston W.L.
        • Morelli J.G.
        Herpes simplex virus-associated erythema multiforme in prepubertal children.
        Arch Pediatr Adolesc Med. 1997; 151: 1014-1016
        • de Ocariz M.
        • Vega-Memije E.
        • Munoz-Hink H.
        A case of herpetic whitlow associated with erythema multiforme.
        Pediatr Dermatol. 1998; 5: 384-385
        • Edmond B.J.
        • Huff J.C.
        • Weston W.L.
        Erythema multiforme.
        Pediatr Clin North Am. 1983; 30: 631-640
        • Huff J.C.
        • Weston W.L.
        • Tonnesen M.G.
        Erythema multiforme.
        J Am Acad Dermatol. 1983; 8: 763-778
        • Huff J.C.
        • Weston W.L.
        Isomorphic phenomenon in erythema multiforme.
        Clin Exp Dermatol. 1983; 8: 409-413
        • Forman L.
        • Whitwell C.P.B.
        The association of herpes catarrhalis with erythema multiforme.
        Br J Dermatol. 1934; 46: 309-311
        • Leigh I.M.
        • Mowbray J.F.
        • Levene J.M.
        • et al.
        Recurrent and continuous erythema multiforme.
        Clin Exp Dermatol. 1985; 10: 58-67
        • Huff J.C.
        • Weston W.L.
        Recurrent erythema multiforme.
        Medicine. 1989; 68: 133-140
        • Brice S.L.
        • Krzemien D.
        • Weston W.L.
        • et al.
        Detection of herpes simplex virus DNA in cutaneous lesions of erythema multiforme.
        J Invest Dermatol. 1989; 93: 183-187
        • Schofield J.K.
        • Tatnall F.M.
        • Brown J.
        • et al.
        Recurrent erythema multiforme.
        Br J Dermatol. 1994; 131: 532-535
        • Renfro L.
        • Grant-Kels J.M.
        • Feder H.M.
        • et al.
        Controversy.
        Pediatr Dermatol. 1989; 6: 43-50
        • Garcia-Doval I.
        • Le Cleach L.
        • Bouquet H.
        • et al.
        Toxic epidermal necrolysis and Stevens-Johnson syndrome — does early withdrawal of causative drugs decrease the risk of death?.
        Arch Dermatol. 2000; 136: 323-327
        • Ting H.C.
        • Adam B.A.
        Stevens-Johnson syndrome.
        Int J Dermatol. 1985; 30: 587-591
        • Ruiz-Maldonado R.
        Acute disseminated epidermal necrosis types 1, 2 and 3.
        J Am Acad Dermatol. 1985; 13: 623-635
        • Roujeau J.C.
        • Stern R.
        Severe adverse cutaneous reactions to drugs.
        N Engl J Med. 1994; 331: 1272-1285
        • Roujeau J.C.
        • Kelly J.P.
        • Naldi L.
        • et al.
        Medication use and the risk of Stevens-Johnson syndrome or toxic epidermal necrolysis.
        N Engl J Med. 1995; 333: 1600-1607
        • Shear N.H.
        • Spielberg S.P.
        • Grant D.M.
        • et al.
        Differences in metabolism of sulfonamides predisposing to idiosyncratic toxicity.
        Ann Intern Med. 1986; 105: 179-184
        • Kakourou T.
        • Klontza D.
        • Soteropoulou F.
        • et al.
        Corticosteroid treatment in erythema multiforme major (Stevens-Johnson syndrome) in children.
        Eur J Pediatr. 1997; 156: 90-93
        • Viard I.
        • Wehrli P.
        • Bullani R.
        • et al.
        Inhibition of toxic epidermal necrolysis by blockade of CD95 with human intravenous immunoglobulin.
        Science. 1998; 282: 490-493
        • Raimer S.S.
        • Sanchez R.L.
        Vasculitis in children.
        Semin Dermatol. 1992; 11: 49-56
        • Saulsbury Ft.
        Henoch-Schonlein purpura.
        Pediatr Dermatol. 1984; 1: 195-201
        • Nussinovitch M.
        • Prais D.
        • Finkelstein Y.
        • et al.
        Cutaneous manifestations of Henoch-Shonlein purpura in young children.
        Pediatr Dermatol. 1998; 15: 426-428
        • Golitz L.E.
        The vasculitides and their significance in the pediatric age group.
        Dermatol Clin. 1986; 4: 117-125
        • Tomomasa T.
        • Hsu J.Y.
        • Itoh K.
        • et al.
        Endoscopic findings in pediatric patients with Henoch-Schonlein purpura and gastrointestinal symptoms.
        J Pediatr Gastroenterol Nutr. 1987; 6: 725-729
        • Ansell B.
        • Falcini F.
        Cutaneous vasculitis in children.
        Clin Dermatol. 1999; 17: 577-580
        • Katz A.Z.
        • Gang D.W.
        A five year old girl with skin rash and abdominal pain.
        N Engl J Med. 1980; 302: 853-858
        • Heng M.C.Y.
        Henoch-Schonlein purpura.
        Br J Dermatol. 1985; 112: 235-240
        • Barnhill R.L
        • Busam K.J.
        Vascular diseases.
        in: Elder D. Elenitsas R. Jaworsky C. Lever’s histopathology of the skin. 8th ed. Lippincott-Raven Co, Philadelphia1997: 185-208
        • Van Hale H.M.
        • Gibson L.E.
        • Schroeter A.L.
        Henoch-Schonlein vasculitis.
        J Am Acad Dermatol. 1986; 15: 665-670
        • Amitai Y.
        • Gillis D.
        • Wasserman D.
        • et al.
        Henoch-Schonlein purpura in infants.
        Pediatrics. 1993; 92: 865-867
        • Gonggryp L.A.
        • Todd G.
        Acute hemorrhagic edema of childhood (AHE).
        Pediatr Dermatol. 1998; 15: 91-96
        • Krause I.
        • Lazarov A.
        • Rachmel A.
        • et al.
        Acute hemorrhagic edema of infancy, a benign variant of leukocytoclastic vasculitis.
        Acta Pediatr. 1996; 85: 114-117
        • Legrain V.
        • Lejean S.
        • Taieb A.
        • et al.
        Infantile acute hemorrrhagic edema of the skin.
        J Am Acad Dermatol. 1991; 24: 17-22