Dermatomyositis
Clinical features
Dermatomyositis is an idiopathic inflammatory myopathy with characteristic
cutaneous manifestations. These include a heliotrope rash involving
the periorbital skin, erythematous scaly plaques on dorsal hands with
periungual telangiectasia and joint eruptions (Gottrons’s papules)
and a photosensitive poikilodermatous eruption. The myopathy primarily
affects the proximal muscles, is generally symmetrical, and is slowly
progressive during a period of weeks to months. The diagnosis is made
by the combination of typical skin changes, muscle weakness, elevated
serum CK and typical changes in the neurophysiological studies and muscle
biopsy.
Dermatomyositis in adults over 40 years of age is associated with malignant
disease, particularly ovarian, lung, pancreatic, stomach, and colorectal
cancers, and non-Hodgkin lymphoma. In most patients the tumour is diagnosed
by the time the myopathic symptoms develop. In patients with dermatomyositis,
the risk of cancer is higher in women than men. Except for older age,
there are no clinical or laboratory markers for the presence of an underlying
tumour, and close clinical follow up is indicated for these patients.
Associated antibodies
Antinuclear antibody testing is commonly positive. Many myositis-associated
antibodies have been recognised in dermatomyositis, but none are linked
to tumours.
Treatment
The treatment of patients with cancer and dermatomyositis should be
directed primarily to the tumour. Immunosuppressive treatment is also
very important, and includes corticosteroids, azathioprin and ivIgG.
Selected references:
1. Callen, JP. Dermatomyositis. Lancet 2000; 355: 53-57.
2. Hill CL, Zhang Y, Sigurgeirsson B, et al. Frequency of specific cancer
types in
dermatomyositis and polymyositis: a population-based study. Lancet 2001;
357: 96-100.
3. Dalakas MC. Polymyositis, dermatomyositis and inclusion-body myositis.
N Eng J Med 1991;325:1487-1498
4. Barnes B. Dermatomyositis and malignancy. Ann Int Med 1976;84:68-76
5. Sigurgeirsson B, Lindelöf B, Edhag O, Allander E. Risk of cancer
in patients with dermatomyositis or polymyositis. N Engl J Med 1992;326:363-367
Web edited by Infodoctor
®
|
