Sulphasalazine is used in a range of immune disorders. It can cause interstitial lung disease in some patients.
Patient selection: therapy with sulfasalazine
Mechanism: hypersensitivity reaction
Clinical features:
(1) the patient is being treated with sulphasalazine
(2) the patient develops shortness of breath and/or chronic cough
(3) there may or may not be eosinophilia
(4) the patient shows evidence of interstitial lung disease on imaging studies and/or pathology
(5) the patient improves after withdrawal of sulphasalazine
(6) the patient improves with steroid therapy
(7) exclusion of other causes of interstitial fibrosis
Differential diagnosis:
(1) sarcoidosis
(2) interstitial lung disease associated with the immune disorder being treated
