Dermatopathology Primer of Inflammatory Diseases

Comprehensive Guide to Dermatopathology: A Comprehensive Review for Practitioners and Trainees

Superficial Perivascular, Interface, Spongiotic, and Psoriasiform Dermatitis

This section delves into the histopathology of superficial perivascular, interface, spongiotic, and psoriasiform dermatitis, providing insights into their characteristic features and distinctions.

• Superficial Perivascular Dermatitis: Characterized by a lymphocytic infiltrate primarily located in the superficial dermis, this form of dermatitis often presents with eczematous or erythematous skin lesions.

• Interface Dermatitis: In contrast to superficial perivascular dermatitis, interface dermatitis involves a lymphocytic infiltrate that predominantly infiltrates the epidermis-dermis interface. Clinically, it manifests as blistering or erosive skin lesions.

• Spongiotic Dermatitis: Defined by intercellular edema and spongiosis within the epidermis, spongiotic dermatitis is associated with inflammatory and allergic skin conditions such as atopic dermatitis.

• Psoriasiform Dermatitis: Exhibiting a characteristic pattern of parakeratosis, acanthosis, and elongated rete ridges, psoriasiform dermatitis is commonly observed in conditions like psoriasis and pityriasis rosea.

Lymphohistiocytic Infiltrate, Leukocytoclastic Vasculitis, Panniculitis, and Folliculitis

This chapter covers a range of inflammatory conditions that affect different components of the skin.

• Lymphohistiocytic Infiltrate: Composed primarily of lymphocytes and histiocytes, this infiltrate is often found in drug reactions, lichen planus, and granulomatous diseases.

• Leukocytoclastic Vasculitis: Characterized by the presence of neutrophils and fibrinoid necrosis involving small blood vessels, leukocytoclastic vasculitis can lead to palpable purpura or urticaria.

• Panniculitis: An inflammation of the subcutaneous fat, panniculitis can be localized or systemic and may present with nodules, plaques, or even systemic symptoms.

• Folliculitis: Defined by inflammation and infection of hair follicles, folliculitis can range from superficial to deep and may manifest as pustules, papules, or abscesses.

Nodular and Diffuse Dermatitis and Bullous and Vesicular Dermatitis

This section explores dermatitis that manifests as nodular, diffuse, bullous, or vesicular lesions.

• Nodular and Diffuse Dermatitis: Nodular dermatitis refers to discrete, palpable nodules, while diffuse dermatitis involves a more widespread, erythematous eruption.

• Bullous and Vesicular Dermatitis: Bullous dermatitis involves the formation of blisters, while vesicular dermatitis is characterized by smaller, fluid-filled lesions.

Dermatopathology Hierarchy Infrastructure and Glossary of Terms

The guide also provides an overview of the organizational structure of dermatopathology and a comprehensive glossary of terms essential for effective interpretation of histopathology reports.

Utility for Practitioners and Trainees

This guide serves as an invaluable resource for both established practitioners and trainees in dermatopathology, facilitating revision and recertification in the field. Its systematic approach, comprehensive coverage, and practical insights make it an essential tool for enhancing diagnostic accuracy and patient care.