Differential Diagnosis for a 6-year-old with Itchiness to Bilateral Armpits and Hyperpigmented Macule
- Single most likely diagnosis + Atopic dermatitis (eczema): This is a common condition in children, characterized by itchy, inflamed skin that can lead to hyperpigmentation, especially in flexural areas like the armpits. The bilateral involvement and presence of hyperpigmented macules are consistent with this diagnosis.
- Other Likely diagnoses + Contact dermatitis: This could be due to an allergic reaction or irritant exposure in the armpits, leading to itchy, inflamed skin and potential hyperpigmentation. + Seborrheic dermatitis: Although more common in infants and adults, seborrheic dermatitis can occur in children, causing itchy, oily, flaky patches on the skin, including in the armpits. + Tinea corporis (ringworm): A fungal infection that can cause itchy, circular patches with hyperpigmentation, though it's less common in the armpits.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.) + Lymphoma: Although extremely rare in children, lymphoma can present with skin lesions, including in the armpits, and systemic symptoms. It's crucial to consider this in the differential due to its severe implications. + Neurofibromatosis type 1 (NF1): This genetic disorder can cause skin changes, including hyperpigmented macules (café-au-lait spots), which might be mistaken for other conditions. NF1 has significant implications for the patient's health and management.
- Rare diagnoses + Mastocytosis: A condition characterized by an accumulation of mast cells in the skin, leading to itchy lesions and potential hyperpigmentation. It's rare but should be considered in cases where other diagnoses are ruled out. + Phakomatosis pigmentovascularis: A rare condition combining vascular and pigmentary anomalies, which could present with hyperpigmented macules. It's essential to consider rare conditions when common diagnoses are excluded.