Histologic Diagnosis of Inflammatory Skin Diseases

Syphilis

…ocytes, rather than mostly of histiocytes and plasma cells. Psoriasis lacks plasma cells and histiocytes, and usually involves the superficial plexus only. Granuloma annulare, unlike juxta-articular nodes, exhibits mucin in association with histi…

Histologic Diagnosis of Inflammatory Skin Diseases

Algorithms Predicated on “Nonspecific” Findings

…tuous capillaries in dermal papillae, and no microorganisms = Psoriasis, pustular In infundibular epidermis: + Bacteria = Bacterial infundibulitis + Hyphae = Majocchi”s granuloma + No infectious agents = Any noninfectious suppurative…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…cale-crust that house neutrophils are reminiscent of those in psoriasis, the absence of dilated tortuous capillaries in thin dermal papillae and of elongated rete ridges of about even length militates against that diagnosis. 10.98.4A: Perivascu…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Keratosis Lichenoides Chronica?

…thematosus, pityriasis lichenoides, pityriasis rubra pilaris, psoriasis, mycosis fungoides, or lichen simplex chronicus, but an authentic and distinctive condition that seems to be exceedingly rare. Cause and pathogenesis of it are not known, the cou…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Colors Stereotypical for Diseases Specific?

…whitish blue of argyria, and depigmented scars are examples. Psoriasis scales have a peculiar silvery tinge. Pink and red lesions are usually inflammatory, excepting in nevi, and red tattooing. Yellow and orange lesions are found in xanthoma, and th…

Differential Diagnosis in Dermatopathology

Discussions

The erythroderma of psoriasis and the erythroderma of mycosis fungoides have several attributes histopathologic in common: psoriasiform acanthosis, an infiltrate in the dermis that consists mostly of lymphocytes and is situated especially around and…

Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Parapsoriasis?

“Parapsoriasis. Under this provisional name, Brocq in 1902 grouped several rare and unclassifiable dermatological types, characterized by nonpruriginous erythmato-squamous spots, extremely persistent and rebellious to all treatment. It is ex…

Histologic Diagnosis of Inflammatory Skin Diseases

Pellagra

…syrup disease are identical to pellagra histopathologically. Psoriasis sometimes is marked by pallor in the upper part of the viable epidermis, but it is accompanied then by psoriasiform acanthosis, some rete ridges of which are thin, as are suprapa…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

…= Dermatophytosis Infection by superficial fungi may simulate psoriasis, as is the case here, the crucial attribute differentiating being the presence of hyphae, those being seen better when stained by PAS. 10.22.3A: Pustular dermatitis, surfac…