Rocky Mountain spotted fever in the USA: a benign disease or a common diagnostic error?

azithromycin (1 g) was given for possible chlamydial infection with Reiter’s syndrome. PCR for Neisseria gonorrhoeae and Chlamydia trachomatis from urethral swab was negative, dark fi eld microscopy of the ulcer did not show spirochetes. HIV viral load, Treponema pallidum haemagglutination test, and Venereal Disease Research Laboratory test were negative, as was the test for HLA B27. Although skin lesions were absent, the combination of stomatitis, conjunctivitis, and urethritis was suggestive for Stevens-Johnson syndrome. Incomplete presentation of this syndrome associated with M pneumoniae infection has been reported, 2,3 but exclusively in children. Because of the atypical pneumonia in combination with incomplete StevensJohnson syndrome, a PCR was done on oral swab material taken on the day of admission. This showed the presence of M pneumoniae DNA. Diagnosis was