Differential Diagnosis for White Vesicles on Thigh and Trunk in a 6-year-old
- The following differential diagnoses are considered for a 6-year-old presenting with white vesicles on the thigh and trunk, without erythema or other symptoms.
Single most likely diagnosis
- Molluscum contagisum: This is a common, highly contagious viral skin infection that presents with small, pearly, or flesh-colored lesions, often with a central depression. It is prevalent in children and can appear anywhere on the body, including the thighs and trunk.
Other Likely diagnoses
- Viral exanthem (e.g., varicella or herpes simplex): Although these conditions typically present with erythema and other symptoms, some cases might have a more subtle appearance, especially in the early stages.
- Keratosis pilaris: This condition causes small, rough, sandpapaper-like bumps on the skin, often on the thighs, and can sometimes appear as small, white vesicles.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
- Herpes zoster (shingles): Although rare in children, especially without a history of varicella or immunocompromising conditions, it's crucial to consider due to its potential for serious complications, including postherpetic neuralgia.
- Autoimmune bullous diseases (e.g., pemphigus or pemphigoid): These conditions are rare but can be severe and require prompt diagnosis and treatment to prevent significant morbidity and mortality.
Rare diagnoses
- Pityriasis porphyarmis (porphyria cutanea tarda): A rare genetic disorder that can cause blistering skin lesions, which might appear as white vesicles, although it typically presents with other systemic and cutaneous manifestations.
- X-linked recessive ichthyomimis: A rare genetic condition characterized by the formation of blisters or vesicles, often accompanied by other skin abnormalities and systemic features.