Eczematous Dermatitis Occurring on a Café-au-Lait Spot Long after Laser Radiation
On August 7, 2006, a 40-year-old woman with an itchy erythematosquamous lesion in her left lateral orbital region presented to my clinic. The lesion was a congenital, coin-sized, pigmented macule that had never been treated before. At the age of about 20, her pigmented lesion was treated with laser. Although the pigmentation of the lesion disappeared after laser radiation, it recurred slightly after some time. Thereafter, the pigmentation remained unchanged without any treatment. The patient moved from Tokyo to Niimi City, Okayama Prefecture, in July 2006. Immediately after her relocation, an erythematosquamous change on her pigmented lesion occurred.\nThere was erythema with a slight scale on roundish, sharply defined, light brown macule sized approximately 3 × 3 cm in the left lateral orbital region. The lesion was slightly infiltrated.\nA specimen was obtained from the lesion by biopsy. In the epidermis, there were relatively thick, confluent parakeratosis, moderate acanthosis, irregularly elongated rete ridges of uneven width, mild focal spongiosis and focal liquefaction degeneration of basal cells. Exocytosis of lymphocytes and histiocytes was observed. The basal layer was slightly hyperpigmented. There was moderate lymphohistiocytic infiltration from the dermal-epidermal junction to the papillary dermis. In the subpapillary and superficial reticular dermis, slight to moderate perivascular lymphohistiocytic infiltration was seen. Me-lanophages were scattered from the papillary dermis to the superficial reticular dermis. The histopathological findings of these inflammatory skin reactions were applicable to spon-giotic dermatitis and interface dermatitis together with lymphohistiocytic cell infiltration (fig. ).\nAs for cutaneous appendages, the pilosebaceous apparatus was normal in number and distribution. In the sebaceous glands, one of the sebaceous lobules had sharply defined, circumscribed parts, which were occupied exclusively by small-sized sebocytes (fig. , fig. ). Their size was reduced to almost half or one-third of the size of normal sebocytes. Some of their nuclei were compressed peripherally in the cell body and pyknosis, and the cytoplasm was scanty. In a word, these small-sized sebocytes were degenerative atrophic ones. None of the sebocytes, including the atrophic ones, did show atypia. There was slight lymphohistiocytic infiltration in the periadnexal dermis.\nIn some of the hair follicles, the lowermost portions had inflammatory cell infiltration of lymphocytes and histocytes, in which a small number of eosinophilic degenerative follicular keratinocytes were present.