Retrospective study of dermatomyositis. Discussion of 40 cases consulting a Dermatology Department

Resumen

Abstract
Background. Dermatomyositis (DM) is included in idiopathic infl ammatory miopathies, together with polymyositis, although clinical variants without
muscle involvement are recognized, exclusively showing cutaneous involvement during variable periods of time, or remaining defi nitely amyopathic.
Cutaneous manifestations are so characteristic that a diagnosis may be made even before any muscular involvement occurs. Association to internal
malignancy, organ involvement, and evolution possibilities arouse interest of physcicians and dermatologists.
Material and methods. We retrospectively studied 40 patients (33 females) consecutively seen at the Dermatology Department of Hospital Ramos
Mejía of Buenos Aires between June 1991, and June 2007.
Objective. To analyse this population composition, cutaneous and systemic involvement characteristics, and disease evolution.
Results. The following was found: 23 percent of amyopathic forms (9 of 40), 16.6 percent associated with internal malignancy (6/36), excluding four
cases of childhood/juvenile DM. Malignancies were exclusively gynecological: breast (3), cervix (2), and ovary (1). Lapse between diagnosis of cancer
and DM was from 0 to 2 years.Infrequent skin lesions and complications of these patients were described, in addition to currently accepted cutaneous
criteria for the diagnosis of dermatomyositis. No “fl agellated” erythema lesions or complete antisynthetase syndrome were found. Unsuspected
interstitial lung disease with simple chest X-ray was detected in two cases, both non-positive for anti-Jo1 antibodies. One case of this series appeared
three years after silicone mammary implant as amyopathic dermatomyositis (ADM). One of 4 deaths was caused by breast cancer metastasis and another by aspiration pneumonia with pharyngeal muscle involvement; in the other two cases the cause was not related to DM.
Conclusions. The analysis of the observed cases enables us to understand data about this population composition (prevalence of ADM, prevalence of internal malignancy, negative results for anti-Jo1 antibodies), to include unusual skin aspects, and to detect unsuspected respiratory diseases requiring special studies for early diagnosis. The lack of previous original reported series of DM in our country is highlighted

(Dermatol Argent 2009;15(1):27-36).

Key words: dermatomyositis, polymiositis. Research Article
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