Differential Diagnosis for a 7-year-old with a Suspected Toe Infection
- Single most likely diagnosis:
- Paronychia: This is the most likely diagnosis given the presentation of erythema, swelling, and tenderness surrounding the nail, especially after a recent trauma to the toe. The loose toenail and the application of Neosporin and a Band-Aid suggest an attempt to manage a localized infection.
- Other Likely diagnoses:
- Cellulitis: The presence of erythema and swelling distal to the toe could indicate a spreading infection, which might be cellulitis. However, the absence of drainage and the localized nature of the symptoms make paronychia more likely.
- Onychomycosis (fungal infection of the nail): Although less likely given the acute presentation, a fungal infection could cause nail loosening and surrounding inflammation. However, this typically has a more chronic course.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Osteomyelitis: Although rare, an infection of the bone could occur, especially if the initial trauma caused a deeper injury. This condition requires prompt diagnosis and treatment to prevent serious complications.
- Septic arthritis: If the infection were to spread to the joint, it could lead to septic arthritis, a condition that requires immediate medical attention to preserve joint function and prevent long-term damage.
- Rare diagnoses:
- Erythromelalgia: A rare condition characterized by burning pain, heat, and redness in the hands and feet. It's less likely given the history of trauma and localized infection signs.
- Autoimmune or inflammatory conditions (e.g., psoriatic arthritis): These conditions could present with nail and surrounding tissue inflammation but are less common in children and would typically have other systemic symptoms or a family history.