BUENOS AIRES, ARGENTINA. Itching, scaling, and erythema (abnormal flushing of the skin) are common features of psoriasis, a fairly common skin disorder. One of the main characteristics of psoriasis is an increased concentration of arachidonic acid and its metabolite, leukotriene B4, in and around psoriatic plaque. It is well-established that fish oils suppress the formation of leukotriene B4 so researchers at the University of Buenos Aires Faculty of Medicine decided to investigate whether topical application of a fish oil treatment to skin areas affected by psoriasis would alleviate the symptoms.
Their clinical trial involved 25 patients with psoriasis who were randomly assigned to apply either fish oil or liquid paraffin to their psoriatic plaques and leave them covered for 6 hours overnight under an occlusive dressing. The treatment was repeated daily for a 4-week period. Fish oil proved highly effective in reducing scaling (severity of scaling went from an average rating of 2.91 to 0.32 on a scale from 0 to 4), plaque thickness (from a rating of 2.21 to 0.52), and erythema (from a rating of 2.71 to 0.90). Itching was not relieved by the fish oil treatment. The 4-week liquid paraffin treatment was also effective in reducing erythema, but was significantly inferior to the fish oil treatment in reducing scaling and had no significant effect on itching or plaque thickness. Both treatments were well accepted by the patients and the researchers conclude that they are both clinically effective with the fish oil treatment being superior to the paraffin treatment.
Escobar, S.O., et al. Topical fish oil in psoriasis: a controlled and blind study. Clinical and Experimentology Dermatology, Vol. 17, 1992, pp. 159-62