Inflammatory disorders of the skin are among the most challenging to diagnose for the clinician and the pathologist alike. An accurate diagnosis requires careful integration of the clinical features and histological findings.
Inflammatory dermatoses are the subject of this issue of Pathology Case Reviews, with special emphasis on the pertinent clinical aspects of the disorders. Psoriasis is one of the most common cutaneous diseases, affecting nearly 2% of the population. Dr. McCall reviews the many subtypes of psoriasis and highlights the clinical and pathological findings. The relationship of psoriasis and HIV disease is interesting and is explored in further detail by Drs. Mohr and Hood, who also examine other common skin conditions whose manifestations are altered by HIV, such as seborrheic and eczematous dermatitis, as well as HIV-specific skin diseases such as pruritic papular eruption (PPE) of HIV infection and eosinophilic folliculitis.
One of the fascinating aspects of dermatology and dermatopathology is the ability to diagnose systemic disease by its cutaneous manifestations. Subepidermal blistering diseases are often autoimmune and linked to underlying disorders or medications and are reviewed in detail in this issue. Similarly, granulomatous dermatoses can reflect internal diseases such as inflammatory bowel disease, diabetes mellitus, gammopathy, sarcoidosis and systemic infection and/or immunodeficiency. A case of cutaneous Crohn disease is presented and the broad differential diagnosis of granulomatous disorders of the skin is examined. Calciphylaxis is another systemic disease with cutaneous manifestations. Dr. Zembowicz discusses this debilitating disorder and reviews the most recent advances in its pathogenesis.
The importance of clinical-pathological correlation is arguably best exemplified by alopecia. Drs. Vanderweil, Houk, and Lyle present a patient with frontal fibrosing alopecia and discuss its relationship to lichen planopilaris and the interesting differential diagnosis of scarring alopecia.
Finally, although the theme of this issue of Pathology Case Reviews is inflammatory skin disorders, mycosis fungoides(MF) and its mimics are presented by Drs. Baum and Liu. MF is a condition that is commonly misdiagnosed, sometimes for years, as an eczematous dermatitis. It is included in this issue to emphasize the importance of clinical history and the potential pitfalls of pathological diagnoses of inflammatory disorders.
Dermatopathology is most challenging when a biosy of an inflammatory condition is enountered. It is critical for the pathologist to appreciate the clinical setting in which the biosy was taken and to integrate that knowledge with the pathological features. It is when these two aspects of the patient are married that a meaningful diagnosis is achieved.