The eruption is ill defined, and the pseudoatrophic plaques tend to be arranged in a vertical direction. The pseudoatrophic plaques most often are situated on the neck and upper part of the thorax. Vitamin A deficiency has been believed a possible factor contributing to the cause of pseudoatrophoderma colli. Some authors previously regarded it as a form of parapsoriasis or an epidermal nevus. Pseudoatrophoderma colli also was considered a variant of papillomatosis of Gougerot and Carteaud.
Laboratory tests are within reference range.
Histology may be helpful to exclude the possibility of atrophic lichen planus, lichen sclerosus, poikiloderma, or porokeratosis of Mibelli. The histologic findings in pseudoatrophoderma colli include hyperkeratosis of epidermis with occasional parakeratosis and thinning of the granular layer, acanthosis of some areas with vacuolation and pyknosis of prickle cells, dilatation of superficial blood vessels, and minimal perivascular lymphocytic infiltration in the dermis. Fragmentation of the elastic tissue also has been described in some patients. Mild atrophy of the epidermis was noted only in single cases. In the past, therapy for pseudoatrophoderma colli included the use of quartz lamp, keratolytics, topical corticosteroids, superficial radiation, and oral vitamin A. Spontaneous clearing was reported in 1 patient.