Isotretinoin-induced myositis

Abstract

Retinoid-induced myositis is a phenomenon recognised in multiple case reports. We report a case of isotretinoin-induced myositis in an 18-year-old male patient. This case adds to the published literature as it demonstrates (i) myositis may occur after extended periods of isotretinoin use, (ii) should be considered as a differential diagnosis even when presenting asymmetrically and (iii) can continue to progress clinically and biochemically initially following the suspension of isotretinoin before being effectively treated with corticosteroids.

Figure 1

CT pelvis demonstrating asymmetric expansion of the right gluteus maximum muscle and associated oedema/stranding in keeping with muscle oedema. Fluid seen tracking into the posterior and lateral compartments of the thigh.

Figure 2

MRI pelvis demonstrating extensive inflammation of the right gluteus maximus with subcutaneous oedema.

Figure 3

CT demonstrating resolution of the right gluteus maximus oedema.