Histologic Diagnosis of Inflammatory Skin Diseases

Identification of Basic Patterns: Skin: Nodular and Diffuse Dermatitis

…ure 5.210 A&B. Specific diagnosis of a diffuse dermatitis: leishmaniasis, acute. This dense diffuse dermatitis made up mostly of histiocytes, but also of scattered lymphocytes, can be identified as that of acute leishmaniasis by dot-like organism…

Histologic Diagnosis of Inflammatory Skin Diseases

Cells That Mediate Inflammation (Inflammatory Cells)

Neutrophils, eosinophils, lymphocytes, plasma cells, and histiocytes are called inflammatory cells because they enter tissue during the process of inflammation. A more exact designation for them is “cells of an inflammatory process”; the…

Histologic Diagnosis of Inflammatory Skin Diseases

Leprosy

Leprosy Synonyms Hansen’s disease Lepra Presentation stereotypical Age and sex Young adults of both sexes who live in endemic areas Distribution of lesions Localized in indeterminate and tuberculoid types; widespread and symmetrical in lepro…

Histologic Diagnosis of Inflammatory Skin Diseases

Applicable Terms

ABSCESS [L. abscessus (a going away)]: Clinically, a circumscribed collection of pus and histopathologically a localized collection of neutrophils. An abscess may form in the epidermis, both surface and infundibular, eccrine ducts, dermis, and subcu…

Differential Diagnosis in Dermatopathology

Discussions

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

Tuberculoid leprosy vs. Sarcoidosis

An inflammatory process caused by Mycobacterium tuberculosis. In the skin, it may be primary as a consequence of direct inoculation (tuberculosis verrucosa cutis) or secondary to a focus of tuberculosis in another organ (the lung for lupus vulgaris,…

Histologic Diagnosis of Inflammatory Skin Diseases

Tuberculosis

Tuberculosis Synonyms Lupus vulgaris Presentation stereotypical Age and sex Any age in both sexes, usually adults Distribution of lesions Localized or widespread, depending on the manifestation specific of the disease Individual lesions Papules, pla…

Histologic Diagnosis of Inflammatory Skin Diseases

Syphilis

Syphilis Synonyms Lues Presentation stereotypical Age and sex Young, sexually active adults of both sexes Distribution of lesions Localized (usually to genitalia) as a chancre of primary syphilis, widespread lesions in secondary syphilis, and locali…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

Images 10.95.1A: Nodular dermatitis, granulomatous + 10.95.1B: Epithelioid histiocytes aligned in a palisade around foci of degenerated collagen and necrosis of inflammatory cells, the histiocytes in turn being encircled by lymphocytes =…