Hello I really appreciate your concern for your husband. Swelling in perineum might be related to abscess, cellulitiy, fruncle or folliculitis. He may require a course of antibiotics under medical supervision Meanwhile I would advise him to take analgesic like acetaminophen and ibuprofen combination for pain relief. Instead of epsom salts bath, sitz bath with hot water may help him. In my opinion he should visit to general surgeon or emergency care for physical examination and battery of investigation like blood for CBC, Liver function test, blood sugar and urine test as well as prescription for antibiotics. Hope this answers your question please feel free to ask for follow up question I will gladly answer you. Best wishes