Differential Diagnosis
- Single most likely diagnosis
- Interdigital candidiasis or bacterial infection (e.g., erythrasma): The patient's symptoms of redness, pain, and swelling between the toes, particularly in the 2nd and 3rd toe, are consistent with an interdigital infection. The initial redness on the lateral side of the great toe may have been a separate, less severe infection or an early sign of the current infection.
- Other Likely diagnoses
- Ingrown toenail: The patient's description of a painful "ball" under the toe and swelling could be indicative of an ingrown toenail, especially if the nail is pressing into the surrounding skin.
- Cellulitis: The redness and swelling on the anterior foot and between the toes could be signs of cellulitis, a bacterial skin infection.
- Morton's neuroma: The patient's complaint of a painful "ball" under the toe could be consistent with Morton's neuroma, a condition where a nerve in the foot becomes irritated.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Osteomyelitis: Although less likely, osteomyelitis (a bone infection) could present with similar symptoms, such as pain and swelling in the foot. If left untreated, osteomyelitis can lead to serious complications.
- Deep vein thrombosis (DVT): While the patient's symptoms are more localized to the toes, DVT can cause redness and swelling in the foot and leg. If missed, DVT can lead to life-threatening pulmonary embolism.
- Gas gangrene: This rare but serious infection can cause severe pain, swelling, and redness in the affected area. If not promptly treated, gas gangrene can be fatal.
- Rare diagnoses
- Gout: Although the patient's symptoms are not typical of gout, it is possible that the pain and swelling could be related to a gouty attack.
- Erythromelalgia: This rare condition causes burning pain, redness, and swelling in the feet and hands. While unlikely, it could be considered in the differential diagnosis.