Acta Dermato-Venereologica

Antinuclear antibodies (ANA) were studied in patients receiving PUVA therapy. Ten patients out of 124, (8%), considered for PUVA had ANA prior to therapy. During PUVA treatment ANA appeared in 34 out of 100 patients. Eight patients with ANA initially were treated and in 4 of them a significant increase in ANA titre was noted. A statistically significant difference was noted, when the first and last ANA tests for each patient were compared. No such difference was seen in a control group consisting of 33 patients. All PUVA patients generating ANA were evaluated clinically and with a laboratory screening. This evaluation was negative in all patients except one who developed ANA of the nucleolar staining pattern together with symptoms consistent with a collagen vascular disease. The ANA titres were generally low and the staining pattern was of the homogeneous type in all patients but one.

PUVA therapy has been reported to induce antinuclear antibodies (ANA). The generation of ANA following ultraviolet irradiation was studied experimentally in albino mice. When treated with long wave ultraviolet radiation (UVA) from blacklight fluorescent tubes a significant number of animals developed positive ANA titres, whereas no change was noted in groups, treated with PUVA, 8-methoxypsoralen only or medium wave ultraviolet irradiation (UVB) respectively. The tendency for UVA-irradiated mice to develop ANA was stronger when higher ANA titres were compared. UVA induces ANA in mice, and PUVA-induced ANA may be due to the UVA component of this therapy.

A case of acanthosis nigricans associated with a metastatic adenocarcinoma is presented. To our knowledge this is the first one reported in the literature. The primary tumour is unknown, but it is presumably a cholangiocarcinoma. The skin changes preceded the detection of malignancy by 2 years, during which the skin lesions progressed though the patient was still in good health. If malignant acanthosis nigricans is suspected and the underlying malignancy cannot be found at the initial screening, repeated screenings are necessary because of the time factor.