Eosinophilic pustular folliculitis (EPF), eosinophilic folliculitis, is also known as “Sterile eosinophilic pustulosis” or “Ofuji disease“. It is a skin condition characterized by itchy, red or skin-colored bumps and pustules. The root cause is unknown but this skin disorder commonly appears on individuals with HIV. Remember that HIV is not the root cause because it can be found in HIV-negative people. The causes may be something which is often a feature of immunodeficiency.
Eosinophilic means relating to eosinophils – a type of immune cell (white blood cell). It is named because of the fact that skin biopsies of this disorder found these cells.
The use of term folliculitis seems not to be completely true because palms and soles may rarely develop similar papules and pustules and there are no follicles in these areas.
How many types of EPF
The variants of this disorder are contoversial because the underlying cause is unknown. As I know, there are 3 main variants of eosinophilic folliculitis as below:
- Classic EPF – mostly occurring in adults in Japan
- HIV-associated EPF, it is also referred to as immunosuppression-associated EPF
- Infantile EPF – with onset from birth or within the first year of life
How does EPF look like
Eosinophilic pustular folliculitis characterized by red, skin-colored dome shaped bumps and pustules surrounding hair follicles and typically appear on the upper body (face, scalp, neck), the abdomen, trunk, and legs. The symptoms look like acne or other types of folliculitis.
Rarely, these are larger red irritable wheal-like patches similar to urticaria. Long lasting cases develop dermatitis or a form of prurigo presumably because of the itching and scratching.
How is eosinophilic folliculitis diagnosed?
- Skin biopsy found eosinophils around affected area
- Blood tests show a small rise in eosinophil cells and IgE, and a dicrease in IgG and IgA levels.
- Regarding to HIV-associated EPF, levels of CD4 lymphocyte cells drop below 300 cells/mm3
What is the cause of eosinophilic folliculitis of HIV?
Immunodeficiency appears to lead to increased risk of allergic-type skin diseases. There is no proof that bacterial, fungal or viral secondary infection is the cause, although some researchers have postulated overgrowth of malassezia or demodex (the hair follicle mite) might be involved.
Another theory is that there is a change in the immune system causing eosinophils to attack the sebum (oils produced in the skin) of sebaceous gland cells.
What is the treatment for eosinophilic folliculitis?
In patients with HIV, EPF is likely to improve with Highly Active Anti-Retroviral Treatment, as CD4 cell counts rise above 250/mm3.
Other treatments that may be effective include:
- Indomethacin and other nonsteroidal anti-inflammatory drugs are reported effective in up to 70% of cases of eosinophilic folliculitis
- Tetracycline antibiotics
- Other antibiotics including metronidazole
- Topical steroids
- Calcineurin inhibitors such as tacrolimus ointment
- Oral antihistamines such as cetirizine
- Permethrin cream (topical insecticide)
- Nicotine patches
- Isotretinoin and acitretin.