Actinic reticuloid: an immunological investigation providing evidence of basement membrane damage

Twelve cases of actinic reticuloid have been investigated using immunological procedures. It was shown that the patients were fully competent immunologically and no evidence was found to support a photo‐allergic mechanism in the pathogenesis of the disease. The importance of the basement membrane zone as a site of tissue damage was observed by the finding of a localized band of fibrin deposition in this site using immunofluorescence techniques. Further, it was shown that, by irradiating uninvolved skin at 360 nm, an infiltrate simulating a lymphoma was produced by 24 h. It was concluded that the fibrin deposition was secondary to the infiltrate.