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folliculitis

Infection with inflammation of an upper segment of hair follicle. Etiology: 1) bacterial a) Staphylococcus aureus (most common) - MRSA b) Propionibacterium acnes c) Pseudomonas aeruginosa (hot tub folliculitis) d) gram-negative bacilli - associated with systemic antibiotic therapy of acne vulgaris [5] - often Escherichia coli [5] e) secondary syphilis 2) fungal - Dermatophytes - Pityrosporum - Candida 3) viral - Herpes simplex - HIV (eosinophilic folliculitis) 4) Demodicidosis (Demodex) 5) predisposing factors - shaving hairy regions - occlusion of hairy areas facilitates growth of microorganisms - high temperature & humidity - topical glucocorticoids - systemic antibiotics promotes growth of resistant organisms - diabetes mellitus - immunosuppression (systemic glucocorticoids) [3] Epidemiology: - inadequate water chlorination hot tub, whirlpool or less commonly, public swimming pool - common among athletes [5] Pathology: * histopathology images [8] Clinical manifestations: - pruritic eruption - hair follicle-centered erythematous papules with pustules - trunk, axilla, buttocks, & proximal extremities most commonly affected (areas with short, coarse hair) [4] - scalp commonly affected [5] - Pseudomonas folliculitis begins 1-4 days after bathing (hot tub etc) * images [6,7,8] Laboratory: 1) Gram's stain 2) KOH preparation for fungal hyphae 3) culture of pustule - concern for MRSA or other drug-resistant organism 4) skin biopsy * diagnosis can be made from clinical presentation [5] Complications: - pseudomonas folliculitis - fever - external otitis - breast abscess - painful plantar nodules - bacteremia Management: 1) prophylaxis - adequate chlorination of hot tubs & swimming pools 2) general measures - wash with antibacterial soap, benzoyl peroxide, or chlorhexidine 3) Bacterial folliculitis a) Propionibacter acnes (see acne) b) Staphylococcus aureus - mupirocin ointment BID to involved skin & nares - dicloxacillin 1-2 g/day divided QID for 10 days - cephalexin (Keflex) 1-2 g/day divided QID for 10 days - erythromycin 1-2 g/day divided QID for 10 days - minocycline 1-2 g/day divided QID for 10 days for MRSA c) Pseudomonas aeruginosa - in most cases spontaneous resolution within 7-14 days - ciprofloxacin 500 mg BID if persistent [5] - ceftazidime or cefepime for severe or prolonged cases or immunosuppressed patients d) gram-negative folliculitis - discontinue current antibiotics - topical benzoyl peroxide - ampicillin 250 mg QID - Bactrim DS BID - isotretinoin 4) fungal folliculitis - itraconazole 100 mg BID for 10-14 days (Pityrosporum, Candida) - terbinafine 200 mg/day (Dermatophytes) - fluconazole 100 mg BID for 10-14 days (Candida) 5) herpetic folliculitis - acyclovir 400 mg TID for 7 days - see Herpes simplex 6) Demodicidosis (Demodex) - permethrin cream

Related

pseudofolliculitis barbae; pili incarnati

Specific

eosinophilic folliculitis Pityrosporium folliculitis

General

hair disease skin infection inflammation

References

  1. Color Atlas & Synopsis of Clinical Dermatology, Common & Serious Diseases, 3rd ed, Fitzpatrick et al, McGraw Hill, NY, 1997, pg 36-43
  2. Harrison's Principles of Internal Medicine, 13th ed. Isselbacher et al (eds), McGraw-Hill Inc. NY, 1994, pg 294
  3. Kaplan DL, Dermclinic Consultant Dec 2005, pg 1563 http://www.ConsultantLive.com
  4. Geriatrics at your Fingertips, 13th edition, 2011 Reuben DB et al (eds) American Geriatric Society
  5. Medical Knowledge Self Assessment Program (MKSAP) 16, 17, 18, 19. American College of Physicians, Philadelphia 2012, 2015, 2018, 2021.
  6. MedicineNet.com Image Collection: Bacterial Skin Diseases. Picture of Folliculitis http://www.medicinenet.com/image-collection/folliculitis_picture/picture.htm
  7. DermNet NZ. Folliculitis (images) http://dermnetnz.org/acne/folliculitis.html - DermNet NZ. Bacterial folliculitis (images) http://dermnetnz.org/bacterial/bacterial-folliculitis.html
  8. Satter EK, MD, Elston DM (images) Medscape: Folliculitis http://emedicine.medscape.com/article/1070456-overview
  9. Elkston CA, Elkston DM Bacterial Skin Infections: More Than Skin Deep. Medscape. July 19, 2021 https://reference.medscape.com/slideshow/infect-skin-6003449