[Henoch-Schönlein purpura associated with pulmonary tuberculosis]

A 34-year-old man was admitted to our hospital because of cough and fever. Chest radiograph showed multiple cavities mainly on the right lung. His sputum was positive for acid-fast bacilli on smear, and he was treated with daily isoniazide, rifampicin and streptomycin. Antituberculous treatment was successfully performed, so acid-fast bacilli of his sputa disappeared on smear and culture. Five months later, he developed a purpuric lesions over both legs accompanied by low grade fever and arthralgia, but proteinuria and abdominal pain could not be observed. Laboratory findings showed a normal platelet count and a normal bleeding time. High levels of serum IgG, IgA, C3 and C4 were evident. ASLO and ASK titer were elevated and they markedly increased within two weeks. A direct invasion of the vessel wall by tubercle bacilli is deniable because antituberculous treatment was successfully continued. Henoch-Schönlein purpura was diagnosed judging from these findings. High levels of ASLO and ASK suggest a preceding streptococcal infection for developing purpura but a possible infectious focus could not be identified. He was treated with 15 mg of prednisolone daily for two weeks and the lesion was subsided. The effect of prednisolone suggests that a subsequent antigen-antibody interaction caused by a streptococcal infection may participate in the formation of the purpura.