What causes scalp pustules?

Scalp Pustules

What causes scalp folliculitis? Folliculitis refers to a process whereby inflammation develops within the wall of a hair follicle. Individuals with folliculitis have redness around the hair follicles and may have pustules, papules and vesicles.

There are many ways to classify folliculitis but these processes are generally classified as infectious, non infectious and perifolliculitis. 
Bacteria, viruses and fungi and yeast can all cause various types of infectious folliculitis. They can cause temporary or permanent hair loss.

The list of non infectious causes is long. Certain medications like topical steroids or topical products like various hair care products can cause folliculitis. A variety of scarring alopecias are on the list of causes of scalp folliculitis including folliculitis decalvans, dissecting cellulitis, acne necrotica, and follicular mucinosis.

Perifolliculitis simply refers to inflammation that surrounds the hair follicles without penetrating through them. Lichen planopilaris is another scarring alopecia and a classic example but there are many others in this class including vitamin A deficiency and lithium toxicity.

A careful history and examination is needed for anyone with a suspected folliculitis. Swabs are essential if there are pustules and one should normally culture any pustules on the scalp. Viral swabs and scrapings for fungi may also be important depending on the situation. A scalp biopsy can sometimes be helpful and becomes mandatory if scarring is seen.