Hi Thank you for asking HCM I have gone through your query.Your problem is most likely photodermatitis.It usually occurs in sun exposed parts.It is better to show a dermatologist and rule out that.Avoiding sun exposure is the best remedy.You can wear full sleeve shirts to avoid sun exposure.Sunscreen application is also helpful in some.Rashes are usually treated by corticosteroid creams or ointments and antihistamines like levocetirizine.Limit the amount of limes, celery, carrots, and figs in your diet, because these contain natural psoralens (sun sensitizers).Avoid natural fruit-based skin lotions and cosmetics, because they may contain sensitizers as well.Hope this may help you. Let me know if you have any further query.