Comparison of muscle-derived serum carbonic anhydrase III and myoglobin in dermatological patients: effects of isotretinoin treatment.

The serum levels of muscle-specific serum carbonic anhydrase III (S-CAIII) and myoglobin (S-Myo) were analyzed in various male dermatological patients of the same age. The mean levels of S-CAIII and S-Myo were essentially similar in patients with acne, psoriasis vulgaris, atopic eczema and tinea, suggesting that common dermatological diseases do not affect the serum levels of the muscle markers. Increased levels of S-CAIII, which is specific for skeletal muscle cells, were found in the acne patients who had been treated with isotretinoin. However, when S-CAIII and S-Myo were studied in 24 patients (16 males, 8 females) before and during isotretinoin treatment, no constant increases in these markers could be observed. When individual patients were followed for several months, transient increases or decreases could be observed. The changes in S-CAIII, or S-Myo, did not correlate with the dose of isotretinoin, nor with the duration of the treatment. The results suggest that systemic isotretinoin does not specifically affect skeletal or myocardial muscles. The increases in these markers observed in the course of dermatological diseases and isotretinoin treatment are obviously due to other factors, such as exercise.