Hypersensitivity pneumonitis possibly caused by riluzole therapy in ALS.

A 69-year-old man with sporadic amyotrophic lateral sclerosis (ALS) presented with complaints of increasing and disabling shortness of breath and dry cough for 3 months. A chest X-ray, taken for routine purposes 6 months before the start of symptoms, was normal. The patient was diagnosed with ALS 33 months before presentation. Riluzole1,2⇓ 50 mg twice daily was started 1 year later. He was treated with omeprazole 20 mg per day for more than 10 years, for a grade IV esophagitis. Ten days before the respiratory complaints started, omeprazole was switched to lansoprazole 15 mg per day. After receiving antibiotics for a total of 20 days, without effect, the patient consulted a pulmonologist, who diagnosed him with pulmonary fibrosis. He was treated with methylprednisolone for 8 weeks (32 mg per day tapered every fortnight). This improved his general condition, but had only a minor effect on the coughing and dyspnea. After methylprednisolone was stopped, the complaints soon recurred and the patient presented himself to our clinic. Clinical examination revealed ALS with predominant lower limb involvement: the patient was capable of walking with a walker, but was restricted …