Hi @CG , there are many possible causes for this, ranging from allergies to fungal infections or heat rash which is common in our local context in Singapore. The first step would be to monitor the rash and observe if any particular activities or exposures cause it to worsen. Practice hygiene and keep the area of skin exposed and dry at home. Unfortunately the remedies for some causes may make the others worse, such as creams containing steroids that may be soothing for some causes, can make fungal infections worse.

If it does not improve, it would be best to have a discussion with a GP to work this out, particularly if your symptoms are getting worse. You may want to do this right away if the rash is extensive (beyond just the upper arms), worsening, causing your child discomfort, or if they have any other symptoms such as fever. This can easily be done online via apps like DoctorWorld that provide video-based consultations, and the attending doctor would be able to prescribe medications and have them delivered to you. Here is a link that shares more about this: https://www.todayonline.com/brand-spotlight/doctor-will-see-you-next-app