Meyerson phenomenon around naevi: resolution after sun exposure?

Meyerson phenomenon (MP) is an inflammatory, some­ times itchy, eczematous eruption usually encircling a pre-existing melanocytic naevus. The terms halo derma-titis and Meyerson's naevus are also frequently used to describe it (1). MP usually appears in otherwise healthy young male individuals, but has also been reported in females and young children (2). Apart from slight itching, no other symptoms usually arise (3). Such a naevus can be mistaken for melanoma or Sutton's naevus (1). In making a differential diagnosis, halo naevus (4), pityriaris rosea (5) and roseola of syphilis should be considered. We report here a case of a man with a history of eczematous reaction and itch involving 3 pre­existing melanocytic naevi at different times. CASE REPORT In March 2009 a 28-year-old man was referred to our outpatient clinic for a two­week history of an eczematous plaque around a pre-existing melanocytic naevus on the right side of his abdomen. Clinical examination revealed a 1 cm, circular, erythemato­ vesicular plaque accompanied by scaling, overlying a 2 mm me-lanocytic naevus. The patient reported severe itch. He was not on any medication, and reported no external contact agent, history of atopy, vitiligo or melanoma. Dermoscopic examination of the lesion revealed intense erythema with scaling and yellow crusts overlying and surrounding the melanocytic naevus. The eczematous manifestation prevented us from examining the naevus pattern. A diagnosis of MP was made, and the patient was started on topical therapy based on corticosteroids and fusidic acid. After 3 weeks the eczema improved and dermoscopic examination showed a regular, reticular pattern with mild scaling and light hypopigmentation encircling the naevus; erythema was absent. Cortico-antibiotic treatment was stopped. After two weeks a relapse of the eczematous manifestation was registered and a similar inflammatory phenomenon involving two other melanocytic naevi developed on the abdomen (Fig. 1). The patient was therefore started on a new course of treatment with topical corticosteroids. At the follow­up visit after one month, the patient presented with complete resolution of all 3 inflammatory manifestations (see Fig. 1); the melanocytic lesions showed no changes, either clinically or dermoscopically. Interestingly, the patient reported whole body exposure in the summer time and low compliance with the prescribed treatment. Eighteen months later, no changes were detected in the involved naevi, with no recurrences of inflammatory background. DISCUSSION The management of MP is controversial; some authors advise surgical excision of the naevus, especially if the le-sion does not respond …