What Causes Fever And Skin Irritation In The Face?

hello, My sister just moved to Greece and in couple of days she got temperature and irritated face skin. she has some spots on face and feeling nauseous. she went to the doctor but they could not find out what it was,and prescribed antibiotics. if it s not ok in 2 days she should visit the dermatologist. i m freaking out :(( she said she feels week and lost some weight. could you please help me ? can it be acclimatization or food poisoning ? thanks