In order to establish the role of human papillomavirus (HPV) in carcinogenesis of epidermodysplasia verruciformis (EV), the presence, the molecular characteristics and the physical state of HPV DNA in a benign lesion, a primary carcinoma and a metastatic carcinoma developing in the same EV patient were studied and compared. Of the 2 HPV DNAs isolated from benign macular lesions, only one (a subtype of HPV 5) was detected in both primary and metastatic tumors. Only one normal species of viral DNA molecule was detected in the benign lesion, whereas most, if not all, viral DNA molecules present in the carcinoma (both primary and metastatic) were aberrant ones. The major viral DNA molecule in the primary carcinoma was a large HPV DNA with duplicated 40% subgenomic segments, and was present as free episomes. The major viral DNA molecule in the metastatic carcinoma was the 40% subgenomic segment itself, lacking the remaining 60% segment of the viral genome, and was integrated within cellular DNA. Thus, HPV DNA was present in tumors at any stage of malignancy, and its molecular characteristics and physical state changed not only with the development but also with the enhancement of malignancy, consistently conserving its defined 40% subgenomic segment as the predominant viral sequences. Our results suggest that HPV 5 may be actually involved in carcinogenesis in EV patients.

Two sisters (non-twins) had impetigo herpetiformis triggered by their first pregnancy. One sister treated with etretinate had good resolution of skin disease. Impetigo herpetiformis is probably a variant of pustular psoriasis and may be provoked or precipitated by factors, such as pregnancy. Both patients shared common HLA antigens (All, AW24, BW44, BW54 and DR6Y).

The distribution of immune deposits in the skin of reversed passive Arthus reaction was investigated using horseradish peroxidase (HRP) as antigen. Free and non‐reacted HRP, after leaking from small vessels, spreads widely in connective tissue, in epidermis, and in hair follicles in a diffuse and homogeneous pattern. When a specific antibody is administered, HRP appears as granular deposits, which can be considered to be immune deposits, and they adhere to the tissues. When sufficient amounts of antibody is intracutaneously administered, these granular deposits are seen at the wall of venules or in the vicinity of the venules, but when a small amount of antibody is injected, the deposits are seen widely in the connective tissue and are apt to be accumulated at the basement membrane of the dermo‐epidermal junction and of hair follicles. Free HRP passes the basement membrane easily, but the immune complexes are considered unable to pass it and are deposited under it.

A patient with follicular mucinosis was treated topically and orally with indomethacin. He had generalized plaques and grouped follicular papules but no signs of cutaneous lymphoma. The skin lesions responded favorably to topical application. Oral administration produced a dramatic improvement. No recurrence has been seen for 5 years after stopping the treatment.

Two cases of epidermodysplasia verruciformis were studied histologically and electron microscopically. Four lesions examined were histologically benign, and had viral particles morphologically similar to that of common human warts. Two lesions on the forehead and the face were histologically in the stages of malignant transformation, the intraepidermal epithelioma and the early invasive squamous cell carcinoma. Similar viral particles were also observed in the upper layers of these 2 lesions. These results suggest that at least some of the virus-induced lesions of epidermodysplasia verruciformis actually become malignant.