Differential Diagnosis for Cellulitis, Erysipelas, and Stasis Dermitis
Single Most Likely Diagnosis
- Cellulitis: This is often the most likely diagnosis due to its high prevalence and the fact that it can present with a wide range of symptoms, including redness, swelling, warmth, and pain in the affected area. Cellulitis can occur anywhere on the body but is most common on the legs.
Other Likely Diagnoses
- Erysipelas: This condition is similar to cellulitis but tends to be more superficial, involving the upper dermis, and is typically caused by beta-hemolytic group A Streptococcus. It presents with well-demarcated, raised, and shiny borders, often on the face or legs.
- Stasis Dermatitis: Also known as venous eczema or gravitational dermatitis, this condition occurs due to poor circulation and fluid buildup in the legs, leading to inflammation and skin changes. It's characterized by a chronic or recurrent pattern, often with associated signs of venous insufficiency like varicose veins.
Do Not Miss Diagnoses
- Necrotizing Fasciitis: Although rare, this is a life-threatening condition that requires immediate recognition and treatment. It presents with severe pain out of proportion to the physical findings, rapid progression of symptoms, and signs of systemic illness. The presence of crepitus (a grating or bubbling feeling under the skin) or bullae can be indicative.
- Deep Vein Thrombosis (DVT): This condition can mimic cellulitis or stasis dermatitis but requires urgent anticoagulation to prevent pulmonary embolism. Look for unilateral leg swelling, warmth, and pain, especially if there are risk factors like recent travel, surgery, or cancer.
Rare Diagnoses
- Mycobacterial Infections: Such as those caused by Mycobacterium marinum, which can cause skin infections that resemble cellulitis, especially after exposure to contaminated water.
- Fungal Infections: Like sporotrichosis, which can cause a chronic, nodular lesion that can mimic cellulitis or stasis dermatitis, particularly in gardeners or those with exposure to soil and plants.
- Erythema Nodosum: An inflammatory condition characterized by tender red nodules, typically on the shins, which can be mistaken for cellulitis but is often associated with systemic diseases or drug reactions.