Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Pityrosporum Folliculitis and Demodectic Folliculitis?

…, Rapini RP, eds. Dermatology. London: Mosby, 2003: 554. The infundibulum of a normal epidermis houses more, and more varied, organisms than any other nook or cranny in the skin. In addition to corneocytes and sebaceous secretion, lodged in infundib…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…11.10.1A: Infundibular plug of corneocytes in a widened infundibulum + 11.10.1B: A cast of parakeratotic cells in the dilated infundibulum = Keratosis pilaris ┬áChanges identical to these are seen in lichen spinulosus, a variant clinical of…

Histologic Diagnosis of Inflammatory Skin Diseases

Pyoderma gangrenosum

…ls mostly; lymphocytes around venules Neutrophils filling the infundibulum Remnants of infundibular epithelium in and around an abscess in the reticular dermis, a sign of rupture of an infundibulum stuffed with neutrophils Subcorneal pustule, if pres…

Histologic Diagnosis of Inflammatory Skin Diseases

Applicable Terms

…“cystic” acne vulgaris. An abscess centered in an infundibulum is known as a furuncle (Fig. 3.2A), it being caused in most instances by Staphylococcus aureus. A carbuncle represents confluence of furuncles (Fig. 3.2B). Abscesses of noninf…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Apocrine Miliaria?

…ent by spongiosis of an apocrine duct at its juncture with an infundibulum that has earned Fox-Fordyce disease the alternative title “apocrine miliaria.” What does apocrine miliaria have in common pathogenetically with eccrine miliaria? N…

Histologic Diagnosis of Inflammatory Skin Diseases

Lichen planus

…because the lichenoid infiltrate of lymphocytes destroys the infundibulum and follicle, the result being permanent alopecia. Differential diagnosis histopathologic Lichen planus-like drug eruption: Numerous necrotic keratocytes, some of them in clu…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…217;s granuloma) The hair was spewed into the dermis when an infundibulum, stuffed with neutrophils, ruptured. The incipient granulomatous inflammation represents a foreign body reaction to contents of that infundibulum. 10.38.2A: Pustular der…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Eruptive Vellus Hair Cyst?

…st, instead of resembling a sebaceous duct is like that of an infundibulum, and the contents of the cyst, instead of being mostly lipid are corneocytes. A sebaceous duct normally enters the infundibulofollicular unit at the junction of infundibular e…

Histologic Diagnosis of Inflammatory Skin Diseases

Pattern Analysis in Historical Perspective

…ecause epithelial structures are devoid of blood vessels. The infundibulum is epithelial, being as it is as much a constituent of epidermis as is surface epidermis. Pustular dermatitides, therefore, can be divided rationally into those of infundibula…