The present case report describes a 10-year-old boy with clinical hist
ory of steroid-dependent asthma who developed severe exacerbation of h
is respiratory symptoms upon isoniazid administration. Subsequent cont
rol of his asthma symptoms was re-established and maintained only afte
r isoniazid withdrawal. This case is the first to emphasize the danger
s of isoniazid administration in patients who have asthma.