Unfortunately the most common response to any rash is that "it must be an allergy". Most rashes are not due to an allergy but some other reason such as a viral illness or eczema. Perhaps you should see a Dermatologist if the rash is not settling.
The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical examination, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.