Differential Diagnosis for Raised, Painful, Indurated Area of Erythema on Left Hip with Black Center
- Single most likely diagnosis
- Necrotic lesion (e.g., necrotizing fasciitis or gangrene): The presence of a black center suggests tissue necrosis, which is a hallmark of these conditions. The raised, painful, and indurated area of erythema is also consistent with an infectious or inflammatory process.
- Other Likely diagnoses
- Cellulitis with abscess formation: The erythema and induration could be indicative of cellulitis, and the black center might represent a necrotic area or an abscess.
- Pyoderma gangrenosum: This is a rare skin condition characterized by painful, necrotic lesions that can have a black center.
- Ecthyma gangrenosum: This is a skin lesion associated with Pseudomonas aeruginosa infection, which can present with a black center and surrounding erythema.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Necrotizing fasciitis: Although already mentioned as the single most likely diagnosis, it is crucial to reiterate the importance of considering this condition due to its high mortality rate if left untreated.
- Gas gangrene (clostridial myonecrosis): This is a life-threatening condition that can present with similar symptoms, including a black center and surrounding erythema.
- Malignancy (e.g., squamous cell carcinoma or basal cell carcinoma): Although less likely, it is essential to consider the possibility of a malignant lesion, especially if the lesion is not responding to treatment.
- Rare diagnoses
- Cutaneous anthrax: This is a rare infection caused by Bacillus anthracis, which can present with a black eschar (scab) surrounded by erythema.
- Spider bite (e.g., brown recluse spider bite): Some spider bites can cause necrotic lesions with a black center, although this is relatively rare.
- Factitial dermatitis: This is a self-inflicted condition where the patient intentionally creates skin lesions, which can sometimes resemble a black center with surrounding erythema.