What over-the-counter creams are available in Singapore for rashes? (photo)

It does sound like your son may have hives or urticaria and has been prescribed with telfast. Telfast is a second generation antihistamine which is a non-drowsy antihistamine as it does not cross the blood brain barrier. While there are not many studies on the long term use of the antihistamines, it is generally believed that the 2nd generation antihistamines are safe for use in the long term. We must always weigh the risks vs benefits of taking the medicines for the long term, but the risks with long term antihistamines is low.

Thank you for the question. It is difficult to be sure from the clinical photos and you should visit your doctor/dermatologist for a thorough history and physical examination for a proper diagnosis. Some possibilities include pityriasis rosea, secondary syhilis and viral exanthem. But I do advise to see your doctor to confirm the diagnosis.