Allergic Contact Dermatitis From a Polyester Trouser Mimicking Atopic Dermatitis

Distinguishing flares of atopic dermatitis (AD) from textile allergic contact dermatitis (ACD) can be challenging, as their clinical presentations may appear similar, and patient anamnesis is often unclear [1]. A 23-year-old woman with a history of AD since childhood presented with a recent relapse of eczema on the flexor folds of her limbs, managed with topical corticosteroid therapy. The patient also described an urticaria-like eruption in the groin and popliteal cavity that developed a few hours after wearing dark polyester trousers (Figure 1). Patch testing with the Società Italiana di Dermatologia Allergologica Professionale e Ambientale (SIDAPA) baseline series 2023 (SmartPractice, Italy) revealed a positive reaction (D4) to IPPD 0.1% pet (++), p-phenylenediamine base 1% pet (+), textile dye mix 6.6% pet (++), and paraben mix 16% pet (++). Further patch test with the SIDAPA textile series (SmartPractice, Italy) was positive (D4) for disperse blue 124 1% pet (+) and disperse blue 106 1% pet (+). The anamnesis, clinical findings, and patch test results, combined with improvement after avoidance of dark synthetic clothes, most likely dyed with disperse dyes (DDs), confirmed the textile dye ACD diagnosis. Sensitising substances used in the textile industry include dyes, textile fibres, fixing resins, metal buckles, and contaminants introduced during the industrial process [1-3]. DDs are small, lipophilic, inexpensive molecules widely used in the textile industry for dyeing, especially synthetic fibres [3]. DDs are the leading cause of textile ACD, mainly in non-occupational settings [2]. Textile ACD due to DDs may result from the native molecule, its intermediates, or impurities [4]. Due to the N substitution in the para molecular structure of DDs, cross-reaction with another para compound, such as para-phenylenediamine, is possible [3]. An Italian multicenter study enrolling 277 patients affected by textile contact dermatitis showed that disperse blue 124 (54.5%), disperse blue 106 (28.6%), and disperse yellow 3 (12.3%) were the patch test positive allergens [4]; the large majority (87.5%) of the cases were non-occupational, and synthetic trousers were among the main causes of ACD. Another previous Italian experience published in 1997 reported disperse blue 124 and disperse orange 3 as the DDs most frequently associated with contact allergy [5]. Textile ACD can present in various clinical forms, including eczematous, psoriasiform, pustular, lichenoid, or erythema multiforme-like patterns [4]. DD ACD most commonly appears in areas prone to sweating and where clothing is in close contact with the skin, especially the folds. This clinical presentation can mimic AD, making differential diagnosis sometimes challenging, particularly in patients with current or anamnestic AD [6]. In our patient, the acute eruption following contact with a dark-coloured garment, patch test result, and resolution of symptoms following allergen avoidance supported the diagnosis of DD-induced ACD. A similar case was reported by Mohamoud et al.; however, their patient presented with an overlapping form of AD and textile ACD, and allergen avoidance led to clinical improvement, but AD persisted at the last follow-up [7]. ACD mimicking AD has been reported with other sensitizers, namely isothiazolinones and fragrances, and should be considered during the diagnostic process [8, 9]. Due to European Union regulations restricting the use of disperse dye in fabrics, the incidence of textile ACD has decreased in recent years [6, 10, 11]. However, the globalisation of industrial production and trade may lead to an increased prevalence of tissue induced ACD. Therefore, textile sensitization, particularly to DDs, remains a relevant concern and should be particularly considered during the diagnostic evaluation of patients with AD-like eruption. Claudio Brescia: conceptualization, investigation, writing – review and editing, writing – original draft. Luca Potestio: conceptualization, investigation, writing – review and editing, writing – original draft. Francesca di Vico: conceptualization, investigation, writing – original draft, writing – review and editing. Cataldo Patruno: conceptualization, investigation, writing – original draft, writing – review and editing, validation. Maddalena Napolitano: conceptualization, investigation, writing – review and editing, writing – original draft, validation. The authors have nothing to report. The authors have nothing to report. The patient in this manuscript has given written informed consent to the publication of their case details. The authors declare no conflicts of interest. Data that support the findings of this study are available from the corresponding author, upon reasonable request.