What is Acne-like Breakouts? 痤疮样痘痘到底是什么?

Folliculitis is an infammaiton of the superficial or deep hair follicle on hair-bearing skin due to infectious or non-infectious causes. It can appear anywhere on the skin, except for our palms and soles. They are tender or itchy red spots, and they might have pus in them. Symptoms can vary. You may not feel anything. Sometimes, the infection causes itchy skin. It is also possible for your skin to feel painful. Acne is a kind of folliculitis.


What causes folliculitis?

Folliculitis can be due to infection, occlusion, irritation and certain drugs. Some drugs lead to follicultis, particularly Corticosteroids (steroid acne), Androgens (male hormones), Adrenocorticotrophic hormone (ACTH), lithium, Vitamins B2, B6, and B12, Phenytoin, Isoniazid, Epidermal growth factor receptor inhibitors, Iodides, Bromides, Cyclosporine, Disulfiram, Psoralens, Thiourea, Azathioprine [1,2].


Irritant folliculitis may arise after shaving (pseudofolliculitis barbae of man, lower legs shaving rash of women), waxing, electrolysis or plucking [3,4].

Paraffin-based ointments, Coal tar and adhesive plasters may all result in a sterile folliculitis [5].

Topical steroids may produce a folliculitis. Perioral dermatitis is a facial folliculitis provoked by moisturisers and topical steroids [1].

Human immunodeficiency virus (HIV)-associated Eosinophilic Folliculitis (EF) is a pruritic skin eruption consisting of follicular papules or pustules, predominantly located on the scalp, face, neck, and upper chest.


Bacterial folliculitis is commonly due to Staphylococcus aureus. If the infection involves the deep part of the follicle, it results in a painful furuncles (boils) . A carbuncle is a cluster of several boils.

Hot tub folliculitis or Spa pool folliculitis is due to Pseudomonas aeruginosa (Gram-negative folliculitis), where pH or chlorine levels of water are not balanced. You’ll see a rash of red, round, itchy bumps a day or so after being in the water [5].

Pustules eruption in the facial T-zone and perinasal distribution due to Klebsiella, Escherichia coli, Enterobacter and Proteus spp. (Gram-negative folliculitis). Usually seen in patients with acne vulgaris receiving long-term antibiotic therapy and adult men with oily skin [5].


The most common yeast to cause a folliculitis is Pityrosporum ovale, also known as Malassezia. Malassezia folliculitis (Pityrosporum folliculitis) are red, itchy, pus-filled pimples that show up on your upper body, mostly on your back and chest, but you can also have them on your neck, shoulders, arms and face. Typically occurs in young adults, with aggravating factors including warm weather, occlusion and excessive sebum production. May also develop in association with antibiotic therapy (especially tetracyclines) or iatrogenic immunosuppression (e.g. organ transplant recipients) [6-9].

Candida albicans can also provoke a folliculitis in skin folds (intertrigo) or the beard area. Primarily occures in diabetics. Pruritic satellite pustules surrounding areas of intertriginous candidiasis. Facial lesions may mimic tinea barbae or acne rosacea.


Ringworm of the scalp (tinea capitis) usually results in scaling and hair loss, but sometimes results in folliculitis.

Majocchi Granuloma can be defined as a deep folliculitis due to a cutaneous dermatophyte infection, usually due to Trichophyton rubrum , characteristically develops in women who shave their legs. Additional risk factors include occlusion, immunosuppression, and use of potent topical corticosteroids.


Folliculitis may be caused by the herpes simplex virus.

Herpes zoster (the cause of shingles) may also present as folliculitis with painful pustules and crusted spots.

Molluscum contagiosum, common in young children, may also cause follicular umbilicated papules, usually clustered in and around a body fold.


Folliculitis on the face or scalp of older or immunosuppressed adults may be due to colonisation by hair follicle mites (demodex). This is known as demodicosis.

The human infestation, scabies, often provokes folliculitis, as well as non-follicular papules, vesicles and pustules.


Case Reports


Pyoderma faciale (rosacea fulminans) presents very acutely on the face in a 24-year-old female. The large red bumps, pustules and sores formed with inflamatory infilateate in the upper and mid dermis on forehead. Despite the lesions are deeply inflamed, there are no internal symptoms. No infective organisms are found in bacterial cultures of the affected skin. She was given Tangs herbal medicaiton and achieved clinical clearance in 8 months and with additional 4 months of follow-up review.




  1. Du-Thanh A, Merlet S, Maillard H, et al. Combined treatment with low-dose methotrexate and initial short-term superpotent topical steroids in bullous pemphigoid: an open, multicentre, retrospective study. Br J Dermatol 2011; 165:1337.
  2. Rosenthal D, LeBoit PE, Klumpp L, Berger TG. Human immunodeficiency virus-associated eosinophilic folliculitis. A unique dermatosis associated with advanced human immunodeficiency virus infection. Arch Dermatol 1991; 127:206.
  3. Coquilla BH, Lewis CW. Management of pseudofolliculitis barbae. Mil Med 1995; 160:263.
  4. Perry PK, Cook-Bolden FE, Rahman Z, et al. Defining pseudofolliculitis barbae in 2001: a review of the literature and current trends. J Am Acad Dermatol 2002; 46:S113.
  5.  Jennifer L. Hsiao, Kieron S. Leslie, Amy J. McMichael, Ashley R. Curtis and Daniela Guzman-Sanchez. In: Jean Bolognia Julie Schaffer Lorenzo Cerroni, editors. Dermatology: 2-Volume Set 4th Edition. Elsevier; 2017. 615-623.e3
  6. Crespo-Erchiga V, Florencio VD. Malassezia yeasts and pityriasis versicolor. Curr Opin Infect Dis 2006; 19:139.
  7. Ben Salah S, Makni F, Marrakchi S, et al. Identification of Malassezia species from Tunisian patients with pityriasis versicolor and normal subjects. Mycoses 2005; 48:242.
  8. Jahagirdar BN, Morrison VA. Emerging fungal pathogens in patients with hematologic malignancies and marrow/stem-cell transplant recipients. Semin Respir Infect 2002; 17:113.
  9. Ashbee HR, Evans EG. Immunology of diseases associated with Malassezia species. Clin Microbiol Rev 2002; 15:21.