Differential Diagnosis for Toe Pain/Swelling/Redness with Reflex Triggered by Pain

• Single Most Likely Diagnosis
  • Cellulitis: This is a common bacterial skin infection that can cause pain, swelling, and redness, especially when triggered by a reflex related to pain. Keflex (cephalexin) is often prescribed for such infections, making cellulitis a likely candidate given the context.
• Other Likely Diagnoses
  • Paronychia: An infection of the skin around the nail, which can cause pain, swelling, and redness. It's a common condition that could fit the symptoms described.
  • Ingrown Toenail: This condition occurs when the nail grows into the surrounding skin, causing pain, swelling, and sometimes infection. It could trigger reflex pain and might require antibiotic treatment if infected.
  • Gout: A form of arthritis characterized by sudden, severe attacks of pain, swelling, redness, and tenderness, often in the big toe. It can be triggered by various factors, including diet, and might cause reflexive pain.
• Do Not Miss Diagnoses
  • Osteomyelitis: A bone infection that can cause pain, swelling, and redness. It's less common but critical to diagnose early because it can lead to serious complications if not properly treated.
  • Septic Arthritis: An infection in a joint, which can cause severe pain, swelling, and redness. It's a medical emergency requiring prompt diagnosis and treatment to prevent joint destruction.
  • Deep Vein Thrombosis (DVT): Although less directly related to the symptoms, DVT can cause swelling and pain in the leg and should not be missed due to its potential for severe complications, such as pulmonary embolism.
• Rare Diagnoses
  • Erythromelalgia: A rare disorder characterized by burning pain, heat, and redness in the hands and feet. It could potentially cause reflexive pain but is much less common than other conditions listed.
  • Complex Regional Pain Syndrome (CRPS): A chronic pain condition that can cause severe pain, swelling, and changes in skin temperature and color. It's rare and might be considered if other diagnoses are ruled out.