Folliculitis is a superficial inflammation of the hair follicle caused by injury, chemical irritation, or infection. Furuncles (abscess or boil) and carbuncles occur when folliculitis extends from the hair shaft to deeper tissues.
1.0 Epidemiology and Etiology:
1.1 Age of onset: Children, adolescents, and young adults. 1.2 Sex: More common in boys. 1.3 Etiology: Most commonly MSSA. Community acquired MRSA becoming more common. Outbreaks of P. aeruginosa infections are associated with inadequately chlorinated pools, hot tubs, etc. 1.4 Predisposing factors:
- Chronic S. aureus carrier state (nares, axillae, perineum, vagina)
- Diabetes Mellitus
- Poor hygiene
- Hyper-IgE syndrome (Job’s syndrome)
- Corticosteroid use
2.0 Pathogenesis Folliculitis, furuncles, and carbuncles represent a continuum of severity of S. aureus infection. Portal of entry: Hair follicle, break in the intergrity of skin. MRSA infections often have high morbidity due to delay in administration of effective antibiotic. Control or eradication of carrier state treats / prevents folliculitis, furuncle, and carbuncle formation.
- Inflammation of follicles, primarily hair follicles.
- Folliculitis: Inflamation of hair follicle from:
- Chemical irritation
- S. aureus (most common)
- Streptococcus species
- Mixed bacteria infection.
3.1 Risk factors Folliculitis 3.1.2 Local Trauma
- Surgical wounds or draining abscess
- Aggravates s. aureus folliculitis
3.1.3 Exposure to occlusive dressing
- Adhesive plaster
- Plastic occlusive dressing
4.1 Furuncles usually occur in areas of friction or perspiration. Lesion is usually a firm, tender, red nodule that becomes more painful and may drain pus.
4.2 Known as abscess or boils 4.3 Usually start as folliculitis 4.4 Deep folliculitis – spread to deeper tissue 4.5 Walled off nodule of purulent infection
- Firm or fluctuant
- Fever is uncommon
- Can be at any site
- Most often in areas of friction