Differential Diagnosis for Indentation of the Buttock in a Toddler
Single Most Likely Diagnosis
- Child abuse (non-accidental trauma): This is a common cause of unexplained injuries in toddlers, including indentations or bruises on the buttock. The history provided by the caregiver may not match the severity of the injury, raising suspicion for non-accidental trauma.
Other Likely Diagnoses
- Accidental trauma: Toddlers are prone to falls and accidents, which can result in bruises or indentations on the buttock.
- Fat necrosis: As mentioned in the question, fat necrosis can cause an indentation or lump on the buttock, often due to trauma or injury.
- Insect bites or stings: Multiple insect bites or stings can cause swelling, redness, and indentation on the skin.
Do Not Miss Diagnoses
- Soft tissue sarcoma: Although rare, soft tissue sarcomas can present as a lump or indentation on the buttock. Early detection is crucial for effective treatment.
- Infection (e.g., abscess or cellulitis): Bacterial or fungal infections can cause swelling, redness, and indentation on the skin, and can be life-threatening if left untreated.
- Vascular malformation: A vascular malformation, such as a hemangioma, can cause a lump or indentation on the buttock and may be associated with other systemic symptoms.
Rare Diagnoses
- Lipodystrophy: A rare condition characterized by abnormal fat distribution, which can cause indentations or lumps on the skin.
- Dercum's disease: A rare condition characterized by painful lipomas (fatty tumors) that can cause indentations or lumps on the skin.
- Ehlers-Danlos syndrome: A rare genetic disorder that can cause skin hyperextensibility, joint hypermobility, and other symptoms, including possible skin indentations or lumps.