Several studies using fish oil supplementation as a source of DHA/EPA (combined) have been reported upon in the evidence-based literature with respect to potential benefits on psoriasis severity. Many of these studies have used high dosage of DHA/EPA (combined) ranging from 2-12 g of omega-3 fatty acid per day over extended time periods approaching 4 months in duration in some studies. Some of these studies have shown a clinical benefit while others have not. With respect to higher dosages, it is noteworthy that the Food and Drug Administration in the U.S. considers up to 3g of DHA/EPA (combined) being generally safe per day for the adult population. In general, studies using omega-3 supplementation have been consistent. Recent studies have suggested that the in-hospital infusion (daily) with omega-3 fatty acid lipid emulsions (containing DHA +EPA) may be a promising alternative in some patients such as those with acute guttate psoriasis. Further studies are ongoing in this area based on primary evidence of graphic effects of omega-3 therapy via intravenous supplementation within clinical institutions. These later studies should be regarded as potentially promising research trials which lead follow-up studies with larger patient numbers and varying doses and durations of such therapy before standard clinical usage can be considered.
Again, consultation with your physician and /or a specialist (in dermatology) is advised.