A Clinical Atlas of 101 Common Skin Diseases Chapter 22. Drug Eruptions | Fixed Drug Eruption Distribution Fig. 22-17 Circular, erythematous, eroded patch on the scrotum and circular red-blue plaque on the thigh. Fig. 22-18 Circular hyperpigmented patches are signs of resolution of the process. Fig. 22-19 Semicircular hyperpigmented patch indicates a lesion has resolved. Fig. 22-20 Interdigital, erythematous, rather well-circumscribed patch.