Histologic Diagnosis of Inflammatory Skin Diseases

"Folliculitis" (Infundibulitis)

…a clue to suppurative infundibulitis nearby, the wall of the infundibulum having been breached and neutrophils sent flying widely into the dermis. Laboratory confirmation Specialized stains for bacteria and fungi may be confirmatory, as may be cult…

Histologic Diagnosis of Inflammatory Skin Diseases

Identification of Basic Patterns: Skin: Pustular Dermatitis

…curate, therefore, to characterize a pustule positioned in an infundibulum (Fig. 5.310) as “folliculitis” when the infundibulum is epidermal, not follicular, the follicle being continuous with the infundibulum and consisting of isthmus, s…

Histologic Diagnosis of Inflammatory Skin Diseases

Sebaceous Units

…lar epidermis, the entry of the duct being at the junction of infundibulum and isthmus (Fig. 1.43). On some sites, e.g., the buccal mucosa and vermilion of the lip (Fordyce’s spots), areolae of women (Montgomery’s tubercles), labia minora…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…at linear array in a pleated hair shaft (trichomalacia) in an infundibulum = Trichotillomania ¬†Alterations in the hair pictured are known colloquially as trichomalacia, but the changes do not result from softening of hair, but rather from twisting a…

Histologic Diagnosis of Inflammatory Skin Diseases

Embryologic Development

…ls that not only will differentiate into a follicle, but into infundibulum and apocrine and sebaceous units, too. A second phalanx of follicular germs and the papilla associated with them emanates from surface ectoderm at sites nearly contiguous with…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…rnified layer = Dermatophytosis Suppuration that begins in an infundibulum may extend upward and come to repose beneath the stratum corneum, the result being the subcorneal pustule illustrated here. 10.22.6A: Perivascular dermatitis, psoriasifo…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…hocytes in an arc at the base of a thickened, hypergranulotic infundibulum associated with compact orthokeratosis = Lichen planus, hypertrophic¬†The changes pictured represent lichen simplex chronicus imposed on lichen planus. Signs of lichen planus,…