Folliculitis

Disease description (causes and symptoms)

• Definition and pathophysiology: Folliculitis is localized inflammation of the hair follicles (pores) caused by bacteria (especially staphylococci) or chemical and physical irritation. When bacteria penetrate the hair follicles, they cause superficial pustular inflammation; if they invade more deeply, they may leave nodular or cystic lesions, scars, and hair loss. Rarely, progression to bacteremia can lead to systemic infection.
• Main causes: Triggering factors include infection with Staphylococcus epidermidis or Staphylococcus aureus, mechanical irritation such as shaving or plucking hair, chemical irritation from tar, petroleum, paraffin, and similar substances, and reduced immunity (stress, lack of sleep, overwork, and underlying diseases). Environmental causes, such as hot-tub-related Pseudomonas infection, may also occur.
• Main symptoms: Itching and pain, localized redness, small papules and pustules (yellow pus), pus, localized warmth, and sometimes fever, chills, localized lymph-node enlargement, and, in recurrent cases, scarring or localized hair loss.

Treatment methods

• General principles: Treatment varies depending on the depth and extent of the lesions and the causative organism. If a localized abscess is present, incision and drainage are the priority, and culture of the drained material may be performed if necessary.
• Medication therapy
  • Topical treatment: Topical antibiotic ointments (e.g., mupirocin), antimicrobial or antifungal shampoos (for scalp lesions), or antimicrobial cleansers (such as chlorhexidine). Topical steroids may help relieve inflammation but can worsen infection, so they should be used after the infection is controlled or as directed by a doctor.
  • Systemic antibiotics: Oral antibiotics targeting a broad range of staphylococci (e.g., oxacillin-class or cephalosporin-class antibiotics) may be used. If MRSA is suspected, empirical treatment with trimethoprim-sulfamethoxazole, doxycycline, clindamycin, or other medications may be given, or treatment may be adjusted according to culture results.
• Procedures/surgery: Incision and drainage of a localized abscess may be required, and surgical removal may be necessary for repeatedly recurrent or large nodular lesions.
• Lifestyle management and precautions: Do not scratch or squeeze the affected area; keep razors clean and do not share them; avoid irritants (such as tar and petroleum products); maintain cleanliness to prevent the accumulation of sweat and sebum; and care for wounds after shaving. If the condition is chronic or recurrent, identify and correct the cause, such as shaving habits or hot-tub use.

Checklist before an outpatient visit (including example questions)

• Items/information to prepare
  • Current medications (including prescription and nonprescription medicines and supplements) and any drug allergies
  • When the symptoms started and their course (how long they have lasted and factors that worsen or improve them)
  • Location of symptoms (taking photographs is recommended), extent (localized vs. widespread), and presence or absence of fever or systemic symptoms
  • Previous treatment history (ointments or antibiotics used, and whether incision and drainage were performed) and its effectiveness
  • History of shaving, hair plucking, hot-tub use, or chemical exposure, and risk factors for reduced immunity, such as diabetes or use of immunosuppressants
  • Results of previous culture tests or blood tests, if available (bring them with you)
• Examples of materials to show the doctor at the outpatient visit: photographs of the lesions (from multiple angles, with the date and time noted), a list of recently used medications

Examples of general questions to ask the doctor

• "Is a culture test needed for my lesion? What tests will you perform?"
• "What are the side effects of the antibiotic I am being prescribed, and how long should I take it?"
• "When should I go to the emergency room or seek immediate medical care (for example, based on fever or sudden worsening)?"
• "What changes should I make to my usual lifestyle to prevent recurrence?"

Examples of disease-specific questions

• "Should a culture be performed on the pus from the pustule in this area to check for possible MRSA? How would treatment differ depending on the result?"
• "Because recurrent folliculitis on my scalp (or face) may cause hair loss or scarring, what treatments or management methods are recommended to reduce scarring and hair loss?"