Upper-ear eczema: an unusual case of allergic contact dermatitis due to rubber additives.

A 50-year-old man presented with a chronic pruritic erythemato-desquamative patchy dermatitis with linear fissures involving the upper-ear region bilaterally. He had had this dermatitis for four months. On physical examination no other lesions were found but the patient referred previous similar lesions in the concha of the ear. Previous diagnosis of psoriasis, atopic dermatitis, and acanthoma fissuratum had been made. Patch tests with the Italian baseline series of contact allergens (Società Italiana di Dermatologia Allergologica Professionale e Ambientale-SIDAPA) showed a positive reaction to thiuram mix 1% pet (+ at 48 hours /++ at 72 hours) and mercaptobenzothiazole 1% pet (+ at 48 hours /++ at 72 hours ). Further questioning the patient, he admitted wearing spectacles and using a mobile phone headset for 3-4 hours per day. Analysing the objects, it was found that the eyeglass chain had a black rubber ring (Fig. 1) which touched the area of the upper ear, while the headset had a black rubber ring around the speaker and a black rubber cone around the wire both of which were in strict contact with the site of dermatitis (Fig. 2). The diagnosis of allergic contact dermatitis to rubber components of the spectacles chain and the headset was made. Contact sensitization must be considered in cases of recurrent or chronic localized dermatitis in unusual sites, keeping in mind that the cause may be due to usual allergens in technological and sophisticated instruments.