Scalp conditions are a common concern. There can be many causes for a bad smell in the scalp. Regardless, I would strongly recommend that your boyfriend see his primary care doctor
. In addition, a dermatologist
, or skin specialist, can often be of help in this situation.
There are many causes of a smelly scalp. The first that comes to mind is a fungal infection of the skin. Known as tinea capitis, this often will also cause a rash, however it can be covered by the hair. Occasionally hair loss
in the area can also occur, but may not be noticeable or prominent. These can be easily treated if diagnosed by your doctor. Specific antifungal shampoos are the treatment.
There is also a somewhat less common, but classic syndrome known as the "smelly scalp" syndrome. This is caused by a low grade bacterial infection in the scalp. This is not a hygiene problem, but an infection. This can be treated with specific shampoos. Again, a dermatologist is needed for this diagnosis.
The above are the two most common causes. Given you have already tried aggressive hygiene, I believe that you will need to see your doctor or a dermatologist for further treatment.