Differential Diagnosis in Dermatopathology

Psoriasis on volar skin vs. Dyshidrotic dermatitis

Papules, nodules, vesicles, and sometimes bullae that develop in response to “bites” of arthropods, among the most common offenders being mosquitoes, bedbugs, and mites of scabies….

Differential Diagnosis in Dermatopathology

Discussions

Dermatitis herpetiformis and bullous pemphigoid share several findings, namely, subepidermal vesiculation, fibrin in subepidermal spaces, and a mix of inflammatory cells, among them lymphocytes and some neutrophils and eosinophils. The changes histo…

Differential Diagnosis in Dermatopathology

Dermatitis herpetiformis vs. Bullous pemphigoid

Papules, nodules, vesicles, and sometimes bullae that develop in response to “bites” of arthropods, among the most common offenders being mosquitoes, bedbugs, and mites of scabies….

Histologic Diagnosis of Inflammatory Skin Diseases

Errors and Reasons

Error: Abortive is an accurate modifier of particular pathologic processes, e.g., abortive dermatofibroma, abortive morphea, and abortive T-cell lymphoma. Reason: The idea itself is abortive! For example, what is called “abortive T-cell lympho…

Histologic Diagnosis of Inflammatory Skin Diseases

Scar

Scar Synonyms Cicatrix Presentation stereotypical Age and sex Any age and both sexes Distribution of lesions Usually localized, but sometimes widespread Configuration of lesions Linear, as in a surgical wound Round, as a consequence of an ulcer ind…

Histologic Diagnosis of Inflammatory Skin Diseases

Dermatitis herpetiformis

Dermatitis herpetiformis Synonyms During-Brocq disease Duhring’s disease Presentation stereotypical Age and sex Begins usually in young adults, but may appear for the first time in children or in middle-aged persons; no predilection for eith…

Differential Diagnosis in Dermatopathology

Differential Diagnosis

Pemphigus Vulgaris Grover’s disease, pemphigus vulgaris-like 1. Scale-crusts common 1. Scale-crusts uncommon 2. No parakeratosis 2. Parakeratosis common 3. Suprabasal separation across a broad front 3. Suprabasal separation in small di…

Differential Diagnosis in Dermatopathology

Differential Diagnosis

…isease (transient acantholytic dermatosis) 1. No evidence of excoriation usually 1. Erosions, ulcerations, and scale-crusts, i.e., evidences of excoriation, present often 2. Focal parakeratosis in columns vertical 2. Little parakeratosis as a rul…

Histologic Diagnosis of Inflammatory Skin Diseases

Images

Images 10.44.1A: Perivascular dermatitis, sparse + 10.44.1B: A suprabasal cleft, acanthotic dyskeratotic cells in the spinous and granular zones, and a column of parakeratosis = Grover’s disease Changes in foci of the epidermis iden…