Abstract
A fifty-five year old woman with rheumatoid arthritis developed ptosis, dysarthria, dys-phagia, and general weakness after taking D-penicillamine for seven months. Investi-gation rncluding edrophonium test, single-fiber EMG, and anti-acetylcholine receptor anti-body assay confirmed the diagnosis of myasthenia gravis. She was treated only with pyridostigmine for myasthenia. The myasthenic symptoms gradually subsided after D-penicillamine was discontinued. The anti-acetylcholine receptor antibody levels decreased to the normal range within six months.
We could find seven cases of D-penicillamine-induced myasthenia in the Japanese lit-eratures. Six patients out of eight including ours were female. Comparing with cases reported in other countries, Japanese cases were somewhat younger and developed myas-thenia with smaller dosages. Although it seemed difficult in some cases to determine whether D-penicillamine induced myasthenia or myasthenia occurred by chance, we noted that the clinical spectrum of D-penicillamine-induced myasthenia gravis may be wider than generally accepted.
