Faculty Bibliography

"Nail clipping is a simple technique for diagnosis of several nail unit dermatoses. This article summarizes the practical approach, utility, and histologic findings of a nail clipping in evaluation of onychomycosis, nail unit psoriasis, onychomatricoma, subungual hematoma, melanonychia, and nail cosmetics, and the forensic applications of this easily obtained specimen. It reviews important considerations in optimizing specimen collection, processing methods, and efficacy of special stains in several clinical contexts. Readers will develop a greater understanding and ease of application of this indispensable procedure in assessing nail unit dermatoses."

Bacillus Calmette-Guerin (BCG) vaccine complications in patients with severe combined immunodeficiency (SCID) have been well documented in the literature. We present a case in which the BCG vaccine was administered to an infant who was later diagnosed with SCID and presented with worsening localized BCG reaction upon arrival in the United States. Although the BCG vaccine is not routinely administered in the United States, it is important for physicians to be aware of potential complications of BCG vaccination since prompt treatment can be lifesaving.

We report a case of pediatric onychopapilloma that presented with monodactylous longitudinal erythronychia. Pediatric dermatologists should be aware that this rare, benign nail unit tumor can occur in children. Clinicians should recognize its clinical and histologic presentation and be cognizant of management options.

Localized changes in cutaneous elastic tissue often manifest with flesh-colored, hypopigmented, or yellow papules, plaques, and nodules. We present five children with clinically similar cobblestone plaques composed of multiple hypopigmented, nonfollicular, pinpoint papules located unilaterally over the upper chest. All lesions first appeared at birth or during early infancy. No associated extracutaneous abnormalities have been identified. Histopathology was remarkable for many, thick elastic fibers with elastorrhexis. We believe that these cases represent a distinct and unique variant of connective tissue nevi.

Pigmented onychomatricoma is a rare nail unit tumor that can clinically mimic nail unit melanoma. We report the case of a 63-year-old male with new-onset longitudinal melanonychia involving his right second toe. An excisional biopsy was performed and demonstrated pigmented onychomatricoma. We present this case to alert clinicians of this rare nail unit tumor and the importance of clinicopathologic correlation to avoid misdiagnosis.