Guttate psoriasis is a distinctive acute form of psoriasis which characteristically occurs in children and young adults. Very little specific evidence-based guidance is available in standard texts to help make rational decisions about treatment options. To assess the effectiveness of treatments for guttate psoriasis. We searched the Cochrane Clinical Trials Register (Cochrane Library, Issue 3, 1999), Medline (1966- September 1999), Embase (1988-September 1999), Salford Database of Psoriasis Trials (to November 1999) and European Dermato-Epidemiology Network (EDEN) Psoriasis Trials Database (to November 1999) for terms GUTTATE and PSORIASIS. We also searched 100 unselected RCTs of psoriasis therapy and all 112 RCTs of phototherapy for psoriasis in the Salford Database of Psoriasis Trials for separate stratification for guttate psoriasis. Randomised trials in which patients with acute guttate psoriasis were randomised to different treatments, except those trials examining antistreptococcal interventions which are addressed in a separate Cochrane review. Two reviewers independently assessed trial eligibility and quality. No published report could be found to support or to challenge current commonly used methods of management.Only one trial which met the selection criteria was identified. In this small study of 21 hospitalised patients with guttate psoriasis, intravenous infusion of an n-3 fatty acid rich lipid emulsion was compared with placebo emulsion containing n-6 fatty acids. The n-3 preparation appeared to be of some benefit for patients with guttate psoriasis. There is currently no firm evidence on which to base treatment of acute guttate psoriasis. Studies comparing standard treatment modalities, including phototherapy and topical regimens, are required to enable informed decisions on treatment choices to be made.