Ankylosing spondylarthritis associated with acne conglobata.

We report a case of a rare association between acne conglobata and ankylosing spondylarthritis B27 negative which occurred in a young man. The pathogenetic relationship of the association is not certain, although some researches suggest that the onset of ankylosing spondylarthritis can result from cutaneous disease. Despite the long evolution of ankylosing spondylitis, it is not severe. Thus, the presence of B35 CREG antigens confirm that locus B antigens different from B27 could be associated with a more favourable prognosis of the disease.