A Clinical Atlas of 101 Common Skin Diseases

Atypical Mycobacterial Infections

…by atypical mycobacteria, that is, mycobacteria other than those responsible for tuberculosis and leprosy, expressed clinically as keratotic and crusted papules, plaques, nodules, and tumors that may be punctuated by draining sinuses and by ulcers….

Therapeutic Strategies in Dermatology

Vitiligo: Initial Evaluation

Initial Evaluation Vitiligo Differential diagnosis Tinea versicolor Pityriasis alba Discoid lupus…

Therapeutic Strategies in Dermatology

Erythema Multiforme: Key Points

Key Points Erythema multiforme (EM) is a clinical syndrome marked by either target lesions and/or mucosal erosions. It may be idiopathic or seen in association with infections or medications. EM has been reported in association with herpes simplex…

Dermatology Practical & Conceptual

Enlarging plaque on the face with enlarged supraorbital nerve

…as not performed. What is your diagnosis? Answer: Tuberculoid leprosy with reversal reaction (also called “reactional tuberculoid leprosy” or “low resistant tuberculoid leprosy”). Discussion Leprosy or Hansen disease is a huma…

Histologic Diagnosis of Inflammatory Skin Diseases

Erythema nodosum leprosum

…nodosum leprosum is a particular manifestation of lepromatous leprosy, wholly unrelated to authentic erythema nodosum. True erythema nodosum is a mostly septal panniculitis, whereas erythema nodosum leprosum is a mostly lobular panniculitis. In fully…

Histologic Diagnosis of Inflammatory Skin Diseases


…hem having a bluish cast + 10.57.1C + 10.57.1D = Leprosy, lepromatous¬†When slightly foamy histiocytes have a bluish hue, it means that their cytoplasm houses countless mycobacteria, either those of leprosy of those of infection by atypic…

Differential Diagnosis in Dermatopathology


Tuberculoid leprosy and sarcoidosis are granulomatous dermatitides that resemble one another histopathologically because both consist of aggregations of epithelioid histiocytes in the dermis and, sometimes, in the subcutaneous fat. Despite the simil…

Differential Diagnosis in Dermatopathology

Study By Disease

…odular histopathologically (Quiz #479) Borderline tuberculoid leprosy in conjunction with type I leprosy reaction (Quiz #845) Borderline tuberculoid leprosy with type I reaction (Quiz #844) Borderline-tuberculoid leprosy in conjunction with type I le…

Histologic Diagnosis of Inflammatory Skin Diseases

Applicable Terms

…ng cohesiveness) are predominant in granulomas of tuberculoid leprosy, whereas foamy histiocytes monopolize in granulomas of lepromatous leprosy; both epithelioid histiocytes and foamy histiocytes are present together in granulomas of dimorphous lepr…