Histologic Diagnosis of Inflammatory Skin Diseases

Lichen planus

Lichen planus Synonyms Lichen ruber planus Lichen ruber Presentation stereotypical Age and sex More common in women, especially young and middle-aged adults Distribution of lesions Flexor surface of forearms and wrists, but no site is exempt. Occu…

Histologic Diagnosis of Inflammatory Skin Diseases

Psoriasis

Psoriasis Presentation stereotypical Age and sex Persons of any age and of both sexes Distribution of lesions Localized, e.g., single papule or plaque, or universal, i.e., erythroderma; between these extremes, a preference for elbows and knees, scal…

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…

Histologic Diagnosis of Inflammatory Skin Diseases

Errors and Reasons

Error: Abortive is an accurate modifier of particular pathologic processes, e.g., abortive dermatofibroma, abortive morphea, and abortive T-cell lymphoma. Reason: The idea itself is abortive! For example, what is called “abortive T-cell lympho…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

Images 10.23.1A: Perivascular dermatitis, psoriasiform + 10.23.1B: Orthokeratosis, hypergranulosis, acanthosis, proliferation of infundibular and eccrine ductal keratocytes, and coarse bundles of collagen in vertical streaks = Lichen simp…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

Images 10.2.1A: Perivascular dermatitis, spongiotic and slightly psoriasiform + 10.2.1B: Slight edema of the papillary dermis and scale-crust = Nummular dermatitis ┬áChanges such as these are indistinguishable from those of allergic contac…

Histologic Diagnosis of Inflammatory Skin Diseases

Suction blister

Suction blister Presentation stereotypical Individual lesions Vesicles and bullae Findings histopathologic Fully developed Subepidermal blister beneath which dermal papillae are preserved No infiltrate of inflammatory cells Correlation clinicopath…

Histologic Diagnosis of Inflammatory Skin Diseases

Deep fungal infections

Deep fungal infections Synonyms Mycetoma Subcutaneous mycoses Dermal mycoses Presentation stereotypical Age and sex Any age, both sexes Distribution of lesions Localized or widespread; some infections favor exposed sites; internal organs sometimes…