Psoriatic arthritis in Sub-Saharan Africa

Psoriatic arthritis was infrequently reported in sub-Saharan Africa before the HIV pandemic. Here, we review the available data on the prevalence of psoriatic arthritis in sub-Saharan Africa. No population-based data on the prevalence of psoriasis are available for this part of the continent. Hospital-based studies, nearly all of which were done in dermatology departments, found prevalences of 0.05 to 0.9% in West Africa and 2.8 to 3.5% in South Africa. These substantially lower values compared to those reported in Caucasians despite a higher frequency of the HLA-CW6 allele in black Africans (15.1%) than in Caucasians (9.6%) suggests a role for other factors, which may be environmental and/or genetic. The prevalence of psoriasis seems to have increased markedly in the HIV era (5.15% among HIV-positive individuals). The prevalence of psoriatic arthritis in the general population of sub-Saharan Africa is unknown. Psoriatic arthritis was reported before the beginning of the HIV pandemic (41.6% among 61 patients with psoriasis. Several cases of psoriatic arthritis were identified in HIV-positive individuals (40 to 96%) in hospital-based studies, many of which had small sample sizes. The available studies were biased by limitations to healthcare service access by the population, variability in the diagnostic criteria used, and the sometimes atypical presentation of cutaneous psoriasis, particularly in HIV-positive patients. Thus, the association between psoriatic arthritis and HIV infection deserves to be studied further in sub-Saharan Africa.