What is the likely diagnosis for a child with itching on the trunk and a history of exposure to head lice at school, with the mother also experiencing itching?

Differential Diagnosis

• Single most likely diagnosis:
  • b. head lice: This is the most likely diagnosis given the context that the child's school has an outbreak of head lice and now both the child and the mother are experiencing itching. Head lice are highly contagious and can spread through direct contact, making it plausible for the mother to have contracted them from her child.
• Other Likely diagnoses:
  • a. Chickenpox: Although less likely given the direct mention of head lice in the school, chickenpox could cause itching and is contagious. However, it typically presents with a distinctive rash and fever, which are not mentioned.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
  • Scabies: While not directly mentioned, scabies is a highly contagious skin infestation that causes intense itching and can be spread through direct contact. It's crucial to consider scabies in the differential diagnosis due to its potential for severe discomfort and the importance of early treatment.
• Rare diagnoses:
  • Other parasitic infestations or skin conditions: Such as body lice, fleas, or allergic reactions could also cause itching but are less likely given the context provided. These would be considered rare in this scenario due to the specific mention of head lice in the school setting.