Psoriasis was probably described no later than the first century AD, and the term was coined in the second century. However, a clear association between descriptions recognizable as psoriasis and articular symptoms began in the 19th century. This review was from the English-language, German, and French literature. The development of the differentiation of psoriatic arthritis from clinically similar symptoms, including relevant serologic and radiologic findings and therapeutics with a focus up to the 1960s and the recognition of the efficacy of methotrexate, is reported.