Six patients with chronic symmetrical dermatosis consisting of pink-to-yellow, small oval plaques with slight scaling and following the lines of cleavage are described. All patients were young to middle-aged healthy men. Long-term follow-up confirmed the benign chronic course and lack of response to therapy. Histologic study revealed a lymphocytic perivascular infiltrate that occasionally involved the epidermis in foci, resulting in focal spongiosis, mild acanthosis, and focal parakeratosis. Digitate dermatosis is similar to a chronic form of pityriasis rosea, and no evidence was found for a relationship to parapsoriasis en plaque or mycosis fungoides.
Hu C, Winkelmann RK. Digitate DermatosisA New Look at Symmetrical, Small Plaque Parapsoriasis. Arch Dermatol. 1973;107(1):65-69. doi:10.1001/archderm.1973.01620160037010