Abstract

We reviewed 37 skin biopsies obtained from 35 patients with secondary syphilis during the period of 9 years from January 1980 to June 1988, which had been diagnosed by dark field examination, serologic tests for syphilis, and identification of spirochetes by immunoperoxidase method (avidin-biotin complex) in the skin biopsies. We investigated the histologic features of the skin lesions in secondary syphilis according to the types and patterns of inflammatory cell infiltration in the dermis, vascular reactions and epidermal changes. We matched these histologic findings with the clinical features of the skin lesions. The results were as follows; 1) The histologic patterns of dermal infiltrate in order of frequency were as follows; junctional pattern in 14 biopsies (38%), lichenoid pattern in 10 biopsies (27%), diffuse pattern in 5 biopsies (14%), patchy pattern in 3 biopsies (8%), normal pattern in 3 biopsies (8%) and undertermined in 2 biopsies (5%). 2) The dermal infiltration of plasma cells was found in 24 biopsies (65%). All the biopsies of diffues and lichenoid patterns, 7 biopsies of junctional and one biopsy of patchy pattern showed plasma cells but none in normal pattern. 3) Eosinophils were observed in the dermis in 11 biopsies (30%). There was no difference in incidence of eosinophils in the dermis among morphologic patterns. However, they were frequently seen in the dermis and epidermis of condyloma lata (4 of 7 biopsies). 4) The vascular changes in the dermis included endothelial cell swelling in 23 biopsies (62%), endothelial cell proliferation in 22 biopsies (60%) and vascular dilatation in 10 biopsies (27%). They were most commonly observed in the lichenoid pattern followed by diffuse and junctional patterns. Three cases showed lymphocytic vasculitis. 5) Epidermal changes were seen in all of the biopsies exocytosis, parakeratosis, hydropic change of basal cells, acanthosis, spongiosis, keratinocyte necrosis and hyperkeratosis in the order of frequency. 6) In relation to the clinical manifestations, junctional pattern (14 biopsies) consisted of 6 papulosquamous lesions, 5 macules and 3 papules. Lichenoid pattern (10 biopsies) consisted of 7 papulosquamous lesions and 3 papules. All the biopsies showing diffuse pattern (5 biopsies) appeared in condyloma lata. Patchy pattern (3 biopsies) consisted of 2 macules and 1 papule. All of the normal pattern (3 biopsies) appeared in macules. In conclusion, with dermal and epidermal changes, the acknowlegement of the 5 basic histologic patterns in secondary syphilis seems to be very helpful for the diagnosis of syphilis.

• Keywords: Secondary syphilis;