Also known as alopecia mucinosa
What is follicular mucinosis?
Follicular mucinosis is a rare disorder affecting hair-bearing skin, most commonly on the scalp, head and neck. The name of the condition comes from the accumulation of mucin (jelly-like, semi-liquid material) in the walls of hair follicles. Sometimes the mucin is visible to the naked eye, and the hair follicles are visibly prominent and seem to ooze a clear gelatinous material.
Follicular mucinosis may occur on its own or in association with lymphoma of the skin (15-30% of cases).
Sometimes follicular mucinosis may show up in skin biopsy results for other inflammatory skin diseases. In these cases, it has no particular significance.
What causes follicular mucinosis?
Benign or non-cancerous forms of follicular mucinosis (benign, primary or idiopathic follicular mucinosis) are often of unknown cause.
In the lymphoma-associated form, the underlying condition is usually cutaneous T-cell lymphoma (mycosis fungoides). The condition represents a direct involvement of the hair follicles by lymphoma cells (folliculotropic mycosis fungoides)
Occasionally, other forms of lymphoma (e.g. Hodgkin disease) have also been associated with follicular mucinosis.
What does follicular mucinosis look like?
The head and neck are the most commonly affected sites, especially the scalp and eyebrows. In some cases, the skin lesions can be more widespread.
There are a number of different clinical appearances. Typically there are pink papules (small bumps) or plaques (larger raised or thickened areas of skin) with prominent pores which are the hair follicle openings. The mucin (gelatinous clear material) may ooze from these pores, especially if the area is touched or squeezed. There is usually loss of hair in the affected areas, sometimes accompanied by scarring. The skin lesions may be itchy.
There are no clear distinguishing features between benign or non-cancerous and lymphoma-associated cases.
Benign cases are more likely to occur in younger people. There are a small number of skin lesions which are localised to the head and neck.
Lymphoma-associated cases are more likely to occur in older people. A larger number of lesions occur across multiple body sites.
What other problems can occur with follicular mucinosis?
The most significant association is cutaneous T-cell lymphoma (mycosis fungoides).
How is follicular mucinosis diagnosed?
A skin biopsy is needed to confirm the diagnosis. Even with a skin biopsy, it can be difficult to distinguish between benign cases and lymphoma-associated cases.
Once follicular mucinosis is diagnosed, further assessments are needed to exclude the possibility of an underlying lymphoma. This may include a physical examination, blood tests and imaging studies. Ongoing follow-up is also recommended.
How is follicular mucinosis treated?
Benign follicular mucinosis is usually treated using potent topical corticosteroids or intralesional corticosteroid injections. A range of oral medications may be used including tetracyclines, retinoids and dapsone, antimalarials and corticosteroids. In resistant cases, superficial x-ray therapy may be used.
If an underlying lymphoma is diagnosed, treatment is directed towards the lymphoma.
What is the likely outcome of follicular mucinosis?
Many cases of benign follicular mucinosis burn out and resolve over a few months to years, particularly if the skin lesions are few in number and localised. Other cases can be more persistent, particularly if the skin lesions are more widespread. There can be permanent bald patches if scarring has occurred. If there is an underlying lymphoma, the prognosis is less favourable.
This information has been written by Dr Graham Thom