Resolving Quandaries in Dermatology, Pathology & Dermatopathology

Ichthyoses?

…otes, is an inflammatory process; true ichthyoses are not. The scales in nonbullous congenital ichthyosiform erythroderma tend to be small and delicate, rather than large and platelike. Even if, episodically, fishlike scales appear in nonbullous cong…

Histologic Diagnosis of Inflammatory Skin Diseases

Pruritic urticarial papules and plaques of pregnancy

Pruritic urticarial papules and plaques of pregnancy Synonyms Polymorphic eruption of pregnancy Bourne’s toxemic rash of pregnancy Toxemic rash of pregnancy Toxic erythema of pregnancy Nurse’s late onset prurigo of pregnancy Presentati…

Histologic Diagnosis of Inflammatory Skin Diseases

Photoallergic dermatitis

…pongiotic vesicles Cornified layer either normal or covered by scale-crusts Late Superficial or superficial and deep perivascular and interstitial infiltrate of lymphocytes mostly Uneven psoriasiform acanthosis Slight focal spongiosis Scale-crusts…

Dermatology Practical & Conceptual

Large cell acanthoma: a debate throughout the decades

Have we really concluded what a large cell acanthoma is? Is it a distinct entity, a solar lentigo, a subtype of seborrheic keratosis, or an HPV-induced acanthoma? In 1970, large cell acanthoma (LCA) was first described by Pinkus, as a sharply demarc…

Differential Diagnosis in Dermatopathology

Mucha-Habermann disease vs. Secondary syphilis

An inflammatory disease characterized by lesions with arcuate, annular, and serpiginous outlines and by collarettes of scale on the inner margin of lesions that extend outward in centrifugal fashion, disappearing in months as a rule in the absence o…

Histologic Diagnosis of Inflammatory Skin Diseases

Histiocytosis X

…ly in the upper part of the dermis. What seem clinically to be scales actually are scale-crusts formed by parakeratosis, serum, and inflammatory cells, especially neutrophils. Extravasation of red blood cells in the upper part of the dermis imparts t…

Histologic Diagnosis of Inflammatory Skin Diseases

Pemphigus foliaceus

…ers are apparent, whereas in others no blisters are seen, only scale-crusts being observable. That the scale-crusts are manifestations of a blistering disease may be inferred because they tend to be nearly perfectly round and when they become conflue…

Histologic Diagnosis of Inflammatory Skin Diseases

Gianotti-Crosti disease

…trier’s collections sometimes Focal parakeratosis and/or scale-crusts Late Same as in a lesion developed fully, but with less spongiosis, more acanthosis, and more prominent scale-crusts Correlation clinicopathologic Papules result from spon…

Differential Diagnosis in Dermatopathology

Pemphigus vulgaris vs. Grover’s disease, pemphigus vulgaris-like

An inflammatory disease characterized by lesions with arcuate, annular, and serpiginous outlines and by collarettes of scale on the inner margin of lesions that extend outward in centrifugal fashion, disappearing in months as a rule in the absence o…