To the Editor.—
We report a unique, readily diagnosable dermatosis of children and young adults that we have recognized for the past ten to 12 years. Although generally considered a nuisance cosmetic condition, it has occasionally confounded dermatologists and triggered expensive endocrinologic evaluations.The initial cases were of young children who were brought in by distraught mothers with the vexing problem of "I can't wash the dirt off!" Examination revealed what, indeed, appeared to be dirty-appearing skin, usually around the neck, but sometimes on the arms or trunk. The children woefully recounted their discomfort due to their mother's efforts to scrub their necks clean. The clinical differential diagnoses include pityriasis (tinea) versicolor, Gougerot and Carteaud's reticular and confluent papillomatosis, acanthosis nigricans, pseudoacanthosis nigricans, epidermolytic hyperkeratosis, hyperkera-tosis of the nipple and areola,1 and idiopathic deciduous skin.2The diagnosis is made with a single wipe of the affected area using an alcohol-soaked cotton ball. The "dirt" wipes away, revealing sparkling clean skin beneath, to the chagrin of any (especially maternal) observers.
Duncan WC, Tschen JA, Knox JM. Terra Firma-Forme Dermatosis. Arch Dermatol. 1987;123(5):567-569. doi:10.1001/archderm.1987.01660290031009