UPSC-CMS 2020 — Dermatology

Question 1: Which one of the following is NOT true of Pyoderma gangrenosum?

• A. It is often secondary to heightened immunological reactivity from another disease process
• B. Cultures often show Gram positive Staphylococci (Correct Answer)
• C. Lesions generally respond to steroids
• D. It is characterized by cutaneous ulceration with purple undermined edges

Explanation: ***Cultures often show Gram positive Staphylococci*** - Pyoderma gangrenosum is a **sterile inflammatory dermatosis**, meaning that the ulcers are not caused by bacterial infection. - While secondary infection can occur, the primary lesion itself is **non-infectious**, and therefore, routine cultures of the ulcer base would typically be negative for primary pathogens like *Staphylococci*. *It is often secondary to heightened immunological reactivity from another disease process* - Pyoderma gangrenosum is well-known for its association with underlying systemic conditions, particularly **inflammatory bowel disease**, **rheumatoid arthritis**, and certain **hematologic malignancies**. - Its pathogenesis is thought to involve **dysregulated neutrophils** and an underlying autoimmune or autoinflammatory process. *Lesions generally respond to steroids* - **Corticosteroids** are the first-line treatment for Pyoderma gangrenosum, used to reduce inflammation and promote healing. - Both topical and systemic corticosteroids, such as **prednisone**, are effective in managing the condition. *It is characterized by cutaneous ulceration with purple undermined edges* - The classic presentation of Pyoderma gangrenosum is a rapidly evolving, painful, **necrotic ulcer** with a characteristic **violaceous (purple) undermined border**. - This distinctive appearance helps differentiate it from other types of skin ulcers.