<s>[INST] Hi my husband has had a blisery rash for a while now - the doctor gave him cream and it cleared up and then re apeared on his head - it has now appeared on his chest.  they are dark red patches which blister. [/INST] Hello. Thanks for writing to us at healthcaremagicFluid filled lesions on the body, that are persisting as well as new ones reappearing at places like head and chest, needs to be clinically examined and if required biopsied as well.It could be an immunobullous disorder e.g pemphigus vulgaris or bullous pemphigoid. In each of these disorders, there are well formed bullae. While pemphigus vulgaris presents with fragile bullae that rupture easily and leave behind painful erosions, bullous pemphigoid on the other hand presents with tense bullae along with itching and urticaria.Therefore a thorough clinical examination, supported by appropriate investigations like skin biopsy, is a must to arrive at a diagnosis.I would suggest him to visit to a nearby dermatologist for the same.Regards </s>