Samoan woman, in mid-40s, examination revealed erythematous plaque of upper back and posterior neck. What is your diagnosis?.
D000328:Adult; D001415:Back; D003937:Diagnosis, Differential; D004893:Erythema Nodosum / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D006801:Humans; D009333:Neck; D012595:Scleroderma, Systemic / Q000150:complications / Q000175:diagnosis*; D012878:Skin Neoplasms / Q000175:diagnosis