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A 42-year-old woman is seen for multiple papules and pustules on her back (Figure 117-1). Further questioning demonstrates that she was in a friend's hot tub twice over the previous weekend. The outbreak on her back started after she went into the hot tub the second time. This is a case of Pseudomonas folliculitis or “hot tub” folliculitis. The patient avoided this hot tub and the folliculitis disappeared spontaneously. Another option is to treat with an oral fluoroquinolone that covers Pseudomonas.

Figure 117-1

“Hot-tub” folliculitis from Pseudomonas aeruginosa in a hot tub. (Courtesy of Richard P. Usatine, MD.)

Folliculitis is an inflammation of hair follicles usually from an infectious etiology. Multiple species of bacteria have been implicated, as well as fungal organisms.

  • Folliculitis is a cutaneous disorder that affects all age groups and races, and both genders.
  • It can be infectious or noninfectious. It is most commonly of bacterial origin (Figures 117-2 and 117-3).
  • Pseudofolliculitis or sycosis barbae is most frequently seen in men of color and made worse by shaving (Figure 117-4).1
  • Acne keloidalis nuchae or keloidal folliculitis is commonly seen in black patients, but can be seen in patients of any ethnic background (Figures 117-5 and 117-6).2
  • Eosinophilic folliculitis is described in patients with HIV infection (Figure 117-7).
  • Methicillin-resistant Staphylococcus aureus (MRSA) can pose a challenge to the treatment of folliculitis (Figure 117-8).

Figure 117-2

Close-up of bacterial folliculitis showing hairs coming through pustules. (Courtesy of Richard P. Usatine, MD.)

Figure 117-3

Chronic bacterial folliculitis on the back with scarring and hyperpigmentation. (Courtesy of E.J. Mayeaux, Jr., MD.)

Figure 117-4

Pseudofolliculitis barbae in a black man. Shaving makes it worse and he notes many problems with ingrown hairs. (Courtesy of Jonathan Karnes, MD.)

Figure 117-5

Acne keloidalis nuchae with inflamed papules and pustules on the neck of a young Hispanic man. (Courtesy of Richard P. Usatine, MD.)

Figure 117-6

Acne keloidalis nuchae in a woman demonstrating the folliculitis around the hair follicles and the scarring alopecia that has occurred. (Courtesy of Richard P. Usatine, MD.)

Figure 117-7

Eosinophilic folliculitis on the back of an HIV-positive man. (Courtesy of Richard P. Usatine, MD.)

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