Hi. Skin allergies are a common problem amongst general population and they can be manifested in varied ways and can have varied causes. It could be because of something as simple as a need addition in food plans or a new flower in the garden of your house or any new allergen. Although drugs like levocetrizine or montelukast are good for symptomatic relief, i would suggest the best option for you is to consult a dermatologist and show your skin lesions and then to go for a patch test, that can help in narrowing down as well as identifing the allergen. Eventually, this can be known and the allergen can be avoided, this would be the best treatment plan for you according to me. Do let me know if you have any more questions for me