Hello,
Without examination,confirmation of a diagnosis is tough but it can be contact dermatitis,rash due to friction rub with clothes, dermatitis (atopic, contact, allergic), eczema,excessive sweating causing sweat dermatitis or balanitis(due to an underlying infection (bacterial and fungal as well as other organisms) .
Your husband may try calamine lotion on the rash.He should also maintain hygiene and try to keep the area clean and dry, wear loose-fitting cotton clothing. Also use an antibacterial soap or mild soap like dove.Avoid any kind of cosmetics.He can also use a barrier cream with zinc oxide paste or calamine lotion or a mild steroid cream like dermacort on the rash.Also he has to keep the area adequately moisturized.If the rash is itchy,he can take some antihistaminic like benadryl or Claritin.
If the rash persists then it will be best to get it evaluated from a dermatologist.
Hope it helps .Take care and pls do keep us posted in case you have any additional queries.Kind regards.
Well, all I can really advise is to keep it moist. Try some vitamin E moisturizers to keep it refreshed, and even try using anti-flake shampoos and bodywashes, like Head and Shoulders.