ZILEUTON AND ATOPIC DERMATITIS

Correspondence ZILEUTON AND ATOPIC DERMATITIS To the Editor: I have read with great interest the study made by Woodmansee and Simon.1 The fact that their results are encouraging for further and larger studies on the role of zileuton in atopic dermatitis (AD) is undeniable. In addition, their clear documentation regarding the “weaknesses” of their study deserve appreciation. However, in my opinion, two more weaknesses should be added to their list. First, the scoring system that they used and based on “extent of disease involvement, reflected by skin erythema” seems inappropriate. Objective scoring of only erythema may not reflect the severity of the disease precisely. Scoring AD is difficult, and there is no generally accepted method to evaluate the therapeutic effect of medications on AD. Nevertheless, the severity scoring of AD (SCORAD) index proposed by the European Task Force on AD may be regarded as almost the best one.2 This scoring system combines clinical signs (extent of the involvement, intensity of six items: erythema, edema/papulation, oozing/ crusts, excoriation, lichenification, and drying) with subjective symptoms, such as pruritus and sleep loss. As a result, the authors should have used a more detailed and sophisticated scoring method in the evaluation and management of therapy. SCORAD index may be a time-consuming and impractical. However, their study is a “pilot” study and they have only six patients! Second, AD is a genetically determined, chronic, pruritic inflammatory cutaneous disease which is usually seen in association with bronchial asthma and allergic rhinoconjunctivitis. It may be classified as “mixed” (cases associated with respiratory allergies) and “pure.” Pure AD has “intrinsic” and “extrinsic” variants.3 Re-

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cent data point to a dramatic increase in the number of children with an intrinsic type of AD typically characterized by neither elevated IgE levels nor a specific IgE (specific allergen) sensitization.4 In the intrinsic type of AD, 1) interleukin-4 is not secreted by T cells isolated from spontaneous lesions4; 2) the atopy patch test is always negative5; and 3) skin-derived T-lymphocytes were found to express less interleukin-13 than did T cells from the extrinsic type of AD.4 The outlined data reveal that different immune mechanisms may be operative in AD variants. We classify all AD cases in our dermatology department as mixed or pure (intrinsic or extrinsic) on the basis of clinical findings, skin prick test, total/specific IgE, and atopy patch test results. It may be suggested that allergologic management will bring more benefit in extrinsic and mixed types of AD cases. Although the importance of AD subclassification in the therapy and management of AD cases was not completely understood, it could have been interesting and informative to know more about the clinical features of the six AD cases treated by the authors. MEHMET OKTAY TAS¸KAPAN, MD Department of Dermatology-Allergy GATA H. Pas¸a Teaching Hospital Istanbul, Turkey REFERENCES 1. Woodmansee DP, Simon RA. A pilot study examining the role of zileuton in atopic dermatitis. Ann Allergy Asthma Immunol 1999;83:548 –552. 2. Consensus Report of the European Task Force on Atopic Dermatitis. Severity scoring of atopic dermatitis: the SCORAD index. Dermatology 1993; 186:23–31. 3. Tas¸kapan MO, Kumar P. Role of staphylococcal superantigens in atopic dermatitis: from colonization to in-

flammation. Ann Allergy Asthma Immunol 2000;84:3–12. 4. Kapp A, Werfel TW. Intrinsic and extrinsic atopic dermatitis: is there a difference in pathophysiology? J Eur Acad Dermatol Venereol 1999; 12(Suppl):S11. 5. de Bruin-Weller MS, Knol EF, Bruijnzeel-Koomen CA. Atopy patch testing–a testing tool? Allergy 1999; 54:784 –791.

Response: We appreciate our colleague’s interest in our pilot study of zileuton in atopic dermatitis (AD)1 and would like to respond to his critique. First, the scoring system which was chosen for our study was based closely on a method used in AD studies published in respected, peer-reviewed journals.2,3 We understand that the SCORAD index is a more extensive scoring system, but with so few patients involved in our study and the variability in severity they displayed (some displaying only erythema and edema on examination), trying to measure and analyze a significant score change based on SCORAD may not have reflected the true response that these patients experienced. In summary, our pilot study measured a relatively rough index of objective and subjective clinical response (based on published methods) to see if there was any effect at all from the treatment which would suggest the need for further, larger clinical trials. Second, we appreciate the point that many patients (some atopic, some not) share a similar eczema phenotype, and we have also seen this clinically. All the patients in our study were sensitized to aeroallergens by skin prick testing, and would therefore fit into the author’s “extrinsic or mixed” categories, as opposed to “intrinsic.” The importance of making this distinction is unclear, as the medical management of both groups is similar4 (aside from allergen avoidance measures). However,

ANNALS OF ALLERGY, ASTHMA, & IMMUNOLOGY