Transient Neonatal Pustular Melanosis Workup

Updated: Jan 25, 2019
  • Author: Jennifer Sorrell, MD; Chief Editor: William D James, MD  more...
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Laboratory Studies

The diagnosis of transient neonatal pustular melanosis is usually made by clinical examination.

A Tzanck smear with a cellular stain (eg, Wright-Giemsa stain) or Gram stain of the contents of a pustule reveals a predominance of neutrophils and occasional eosinophils and cellular debris. [5, 11, 12] No evidence of bacterial, yeast, or viral infection is found. Gram stain preparations for bacteria are negative. Blood and skin culture results are negative.


Histologic Findings

Vesicopustules of transient neonatal pustular melanosis show intracorneal and subcorneal collections of neutrophils with occasional eosinophils, mild acanthosis, and some intraepidermal edema. Occasionally, fragmented hairs may be seen in the blister cavity. Dermal inflammatory infiltrate is extremely minimal. Pigmented macules reveal a basket-weave, slightly hyperkeratotic stratum corneum [9] together with hypermelanosis in the epidermal basal cells, but no melanin in the dermis. [8, 14]