J+D=4, I am no doctor but this looks like a dermatological issue. I did a quick search for the top rated dermatologists in your area and this man comes in at number one:
Aside from this I would also try and see another kind of specialist. This could be an immune response to all kinds of things from parasites to MRSA. You said you looked up MRSA and it didn't look like the results you found but it actually can look like what is going on with your husband's head. Often times MRSA presents as fluid-filled cysts that come and go. As for parasites it might sound crazy but it's totally possible for a person to pick them up in Afghanistan. There are hundreds
of kinds of parasites that cause numerous symptoms and while it's a stretch it's something worth looking into. I would start with the dermatologist since this is obviously a skin-related issue and then work your way out from there.
Lastly, I just checked out a doctor's response to a list of symptoms just like your husband's and this is what she said:
They sound like infected hair follicles or boils. Boils are caused by infection of the hair follicle by staph aureus. Apply warm compresses on the bumps and keep the area clean. Drainage of the bump is done only when it becomes soft and forms a head. Take some over the counter pain reliever
and consult a doctor for examination and antibiotics prescription. If there are recurrent boils, then please get your blood sugar levels
I hope it helps. Take care and regards.