Histologic Diagnosis of Inflammatory Skin Diseases

Algorithms Predicated on “Nonspecific” Findings

In this section, algorithms used to reach specific diagnosis are predicated on “nonspecific” findings recognized best at higher magnification. Other changes requisite for specific diagnoses, i.e., denominators that are essential, then ar…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Dermatofibroma?

“Cutaneous fibroma Fibroma simplex Simple fibroma of the skin, as defined above, is a benign tumor, usually appearing solitary, on the upper part of the body and the extremities, which, mainly imbedded in the skin, is only rarely and little…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Common Baldness—an Inflammatory Disease?

“The results also show that inflammation in MPA [male pattern alopecia] is a relatively consistent finding and that, although often insignificant, this frequently leads to an inflammatory folliculitis, perifollicular fibrosis, and unusually…

Differential Diagnosis in Dermatopathology

Atrophic lichen planus vs. Atrophic discoid lupus erythematosus

A red, often ulcerated, boggy papule that represents a hyperplasia of small cutaneous vessels which are "fed" by an arteriole in the subcutaneous fat, the lesion resulting consistently from external trauma, usually in the form of a punctur…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

Images 10.37.1A: Pustular dermatitis, infundibular + 10.37.1B: Numerous Demodex folliculorum and squames in a zone of suppuration = Suppurative infundibulitis of unknown cause Demodex, Pityrosporum, bacteria, sebum, squames, and cornified…

Histologic Diagnosis of Inflammatory Skin Diseases

Identification of Basic Patterns: Skin: Pustular Dermatitis

See Fig. 5.307 A&B. Figure 5.307 Pustular dermatitis. A. Infundibular. B. Surface epidermal. Although most pustules in skin are housed in infundibular epidermis (Fig. 5.308 A&B), many are lodged in surface epidermis (Fig. 5.309 A&B)….

Histologic Diagnosis of Inflammatory Skin Diseases

Images

Images 10.94.1A: Infundibulitis, spongiotic, and peri-infundibulitis, granulomatous + 10.94.1B: Lymphocytes and plasma cells around collections of epithelioid histiocytes = Rosacea, papular  Spongiosis in an infundibulum is a finding comm…

Histologic Diagnosis of Inflammatory Skin Diseases

Erythema elevatum diutinum

…lear “dust” of neutrophils throughout the zones of fibroplasia Scattered eosinophils, lymphocytes, and plasma cells in zones of fibroplasia Prominent vasculature in the lesion; venules with a thick wall, but no fibrin in it Differential…