Picture of the Month—Diagnosis

The Meyerson phenomenon refers to a localized eczematous eruption that has been most commonly described in association with acquired melanocytic nevi (Figure 2); such a lesion may be referred to as a Meyerson nevus.^1,2 The terms halo dermatitis and halo eczema are also frequently used to describe such nevi.^2,3 A halo nevus, however, is a different entity and refers clinically to a nevus that is surrounded by a rim of hypopigmentation. Halo nevi may eventuate in complete disappearance of the associated pigmented lesion, whereas this is not seen with Meyerson nevi.

The Meyerson phenomenon within nevi is not frequently described in dermatology textbooks, though the incidence is likely not rare. Such lesions are most frequently described in otherwise healthy young adult men and demonstrate a predilection for the trunk and proximal extremities.⁴ Published accounts of Meyerson nevi in infancy, such as the case presented here, are much less frequent. The pathogenesis of the eczematous reaction is not known, but immunological mechanisms may be crucial, as discussed by Brandt et al⁵ in describing a patient who developed halo nevi and vitiligo following excision of a Meyerson nevus. Although generally limited to a single melanocytic lesion, involvement of numerous nevi in a single patient has been described.⁶ Pruritus is not uncommon, but involved nevi are not likely to be otherwise bothersome to patients. The Meyerson phenomenon is typically described in association with benign acquired nevi, though a small case series of patients who had involvement of atypical nevi has been reported.⁷

Similar eczematous reactions have also been described in nonmelanocytic lesions, such as seborrheic keratoses, basal cell carcinomas, squamous cell carcinomas, dermatofibromas, keloids, and congenital capillary malformations (eg, port-wine stains).^4,5,8,9 When this phenomenon is observed in overlying nuchal-occipital capillary malformations, the dermatitis may be quite difficult to treat, and in such cases, treatment of the malformation with a pulsed dye laser may expedite resolution of the dermatitis.⁹

The Meyerson phenomenon is generally regarded as self-limited, and as such, the dermatitis should clear within a few months and may not require treatment. However, local treatment of the involved skin with topical midpotency corticosteroids may provide acceptable relief of associated pruritus with possible total clearance of the dermatitis. Despite resolution of the dermatitis, the pigmented lesion will persist.¹⁰ If the eczematous reaction recurs or persists despite treatment, excision of the nevus could be undertaken with expected subsequent clearance of the dermatitis.¹¹ Excision may be limited to the pigmented lesion and need not include the halo of dermatitis.¹²

Histologic evaluation of excised Meyerson nevi will demonstrate nests of nevus cells distributed in a pattern typical of the clinical appearance (eg, compound nevus or with features consistent with a congenital melanocytic nevus). There is no microscopic evidence of regression of the pigmented lesion. Histologic features of parakeratosis, acanthosis, and spongiotic changes noted in association with a superficial chronic lymphocytic infiltrate are consistent with the clinical picture of a superimposed dermatitis.⁴

Correspondence: Joanna M. Burch, MD, Department of Dermatology, University of Colorado, PO Box 6510, Mail Stop F703, Aurora, CO 80045 (joanna.burch@uchsc.edu).

Accepted for Publication: August 1, 2006.

Author Contributions:Study concept and design: Tauscher and Burch. Acquisition of data: Tauscher and Burch. Analysis and interpretation of data: Tauscher and Burch. Drafting of the manuscript: Tauscher. Critical revision of the manuscript for important intellectual content: Tauscher and Burch. Study supervision: Burch.

Financial Disclosure: None reported.