A Clinical Atlas of 101 Common Skin Diseases

Acne Vulgaris

A disease of infundibulosebaceous units, especially infundibula, that may manifest itself solely as noninflammatory lesions, i.e., comedones and intact cysts, or as inflammatory lesions, i.e., papules, nodules, and pustules. The process may resolve…

A Clinical Atlas of 101 Common Skin Diseases

Keratosis Pilaris/Lichen Spinulosus

Keratotic spikes that emerge from dilated ostia of infundibula and are equidistant from one another. The term keratosis pilaris refers to the phenomenon when it presents itself without any distinct arrangement of individual lesions, whereas the desi…

Histologic Diagnosis of Inflammatory Skin Diseases

Applicable Terms

…s. Figure 3.10 Coarse collagen bundles in vertical streaks. COMEDO [L. comedo (glutton)]: A dilated infundibulum stuffed by cornified cells arranged compactly or in laminated fashion, sebaceous secretion, and microorganisms, to wit, bacteria, yeas…

Histologic Diagnosis of Inflammatory Skin Diseases

Algorithms Predicated on “Nonspecific” Findings

…other findings on a face devoid of prominent solar elastosis = Comedo of acne vulgaris + On a face marked by extensive solar elastosis = Comedo of Favre-Racouchot disease + Infundibula plugged by parakeratotic cells = Phrynoderma + Alternation…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

Images 10.1.1A: Pustular dermatitis, infundibular + 10.1.1B: A comedo in association with granulomatous and fibrosing peri-infundibulitis = Acne vulgaris Many of the findings pictured here may be seen in other types of suppura…

Differential Diagnosis in Dermatopathology

Discussions

…rupture of the cyst. Dilated pore must be distinguished from a comedo. Unlike a comedo, dilated pore contains cornified cells arranged in basket-woven and laminate pattern, whereas cornified cells in a comedo are arranged compactly. Furthermore, come…

Histologic Diagnosis of Inflammatory Skin Diseases

Acne vulgaris

…rt of the arms, and upper part of the trunk Individual lesions Comedones, papules, pustules, nodules, cysts, scars Course Usually subsides after puberty but, occasionally, persists for decades Variations clinical 1. Comedonal, papular, pustular, and…