The onset of the muscular illness was relatively acute, with fatigue, low-grade fever, and eosinophilia (>1,000 cells/mm3). Muscle pain and tenderness, cramps, weakness, paresthesias of the extremities, and induration of the skin were the main clinical features. A severe axonal neuropathy with slow and incomplete recovery was associated in some cases. Biopsies of the skin fascia, muscle, and peripheral nerve disclosed a microangiopathy and an inflammatory reaction in connective tissue structures; changes like those observed in scleroderma, eosinophilic fasciitis, and in the toxic oil syndrome. The latter syndrome, caused by the ingestion of contaminated rapeseed oil, occurred in an outbreak in Spain in 1981 and gave rise to a constellation of clinical and pathologic changes that were essentially identical to those caused by contaminated l-tryptophan (Ricoy et al; see also Chap. 41). The two toxins are also closely linked chemically and there have been other more limited outbreaks of the toxic neuropathy, usually from adulterated cooking oil.
The cutaneous lesions and eosinophilia of this syndrome responded to treatment with prednisone and other immunosuppressive drugs, but other symptoms persisted. Severe axonal neuropathy in our patients improved incompletely over several years, leaving one chair-bound with severe distal atrophic weakness after 15 years. Although no longer a problem that is likely to be seen by physicians, it serves as a model for future peculiar myopathic syndromes from adulterated drugs that otherwise would seem innocuous.
Among the many cases of orbital inflammatory disease (pseudotumor of the orbit and Tolosa-Hunt syndrome, as described in Chap. 13), there is a small group in whom the inflammatory process appears to be localized to the extraocular muscles. To this group, the term acute orbital myositis has been applied. The abrupt onset of orbital pain that is made worse by eye motion, redness of the conjunctiva adjacent to the muscle insertions, diplopia caused by restrictions of ocular movements, lid edema, and mild proptosis are the main clinical features and, admittedly, the distinctions from orbital pseudotumor are not clear. It may spread from one orbit to the other. The ESR is usually elevated and the patient may feel generally unwell, but only rarely can the ocular disorder be related to a systemic autoimmune disease or any other specific systemic disease. CT and MRI have proved to be particularly useful in demonstrating the swollen ocular muscles or muscle, and in separating orbital myositis from the other remitting inflammatory orbital and retroorbital conditions (Dua et al). As a rule, acute orbital myositis resolves spontaneously in a matter of a few weeks, although it may recur in the same or the opposite eye. Administration of steroids appears to hasten recovery.
Sarcoid Myopathy, Granulomatous Myositis, and Localized Nodular Myositis
There are undoubted examples of muscle involvement in patients with sarcoidosis, but they seem to be less frequent and less certain than would appear from the medical literature. In some cases, sarcoid myopathy becomes evident as a slowly progressive, occasionally fulminant, painless proximal or distal weakness. The CK levels are elevated. Muscle biopsy discloses numerous noncaseating granulomas. However, such lesions may also be found in patients with sarcoidosis who have no weakness. Treatment with moderate doses of corticosteroids (prednisone, 25 to 50 mg daily) is usually effective in symptomatic cases, but an additional immunosuppressive agent, such as cyclosporine, may have to be instituted if improvement is not evident in several weeks.