Contents
Introduction
Folliculitis is a common skin condition that describes inflammation of the hair follicles. It can be due to infection (bacterial or fungal), inflammation / irritation and / or a blockage of the pores. Common instances include:
- In children – more likely to be bacterial due to staphylococcus
- In shaved skin:
- In adult men – common around the beard area
- In those who shave their legs or arms (more commonly women)
- These cases are typically sterile – and sometimes called pseudofolliculitis
- In teenagers and adults – may occur in sweaty areas – such as around the groin or the buttocks
Most cases are superficial and identify the cause may be difficult. Cases that are deeper in the skin are harder to treat and may result in scarring.
Management may involve:
- Topical agents – such as antiseptics, improve hygiene and occasionally antibiotics (tropical or oral) in more severe cases
- Removal of the irritant – in cases of irritant folliculitis
- Removal of hair – permanent options such as laser may be considered in difficult / recurrent cases
Epidemiology and Aetiology
- Bacterial causes
- Staphylococcus Aureus – most common
- Pseudomonas – associated with outbreaks that occur in public pools / baths / hot tubs. Can cause very intense itching – especially in the groin
- Other Gram-negative organisms are associated with long-term antibiotics use – especially in acne – where tetracyclines (e.g. doxycycline or minocyline) are used long term.
- Fungal causes
- More common in the beard area in men
- May be associated with contact with animals
- Irritant causes
- These will not grow any pathogens if cultured – they are sterile
Risk factors
- Sport participation
- Beard
- Uncut beard
- Shaving “against the grain”
- Clothing friction
- Include tight clothes
- Probably one of the reasons that sports participation is a factor
- Humid environment
- Sweating
- Including not showering as soon as possible after sport – one of the most common presentations I see is in teenagers who are doing sports before or during school and not showering until the evening
- Use of topical steroids
- Reduced immunity
- Diabetes
- HIV
- Cancer
- Other chronic illness
- Immunosupression by medication (e.g. to treat autoimmune disease)
- Skin abrasion
- Carrier of Staph. Aureus in the nose
- Occluded skin – e.g. wet wraps used in eczema
- Adolescent and you adult males have the highest incidence
Pathology
Folliculitis results from disruption of the normal activity of the pilosebacious glands in the skin – in particular it causes an obstruction that affects the flow of these glands.
Deeper infection int he hair follicle can form “furuncles” or “carbuncles” – i.e. bigger pimples!
Presentation
- Rash
- May start of insidiously and become more pronounced
- Raised red lumps on the skin
- May become pustular – small pustules at the centre of the lesion – this does not necessarily indicate infection
- Deeper infections may appear more like pimples or boils
- Typically in hairy areas
- May or may not be itchy
- Often if it not scratched or further irritated it will settle down by itself
- Deeper infections may be tender and painful
- It does not usually cause any systemic infection or systemic signs and symptoms
Differentials
- Acne vulgaris
- Usually can be discerned by location
- Herpes simplex
- Keratosis pilaris
- Contact dermatitis
- Milia
- Periorifical dermatitis
- Insect bites
Investigations
Diagnosis is usually clinical and investigations are not typically required.
- If it is recurrent then swabs may be sent to identify an organism that is involved
- Consider de-roofing any of the pustules to get the contents on the swab
- Also consider testing for diabetes in those with recurrent episodes
- If the diagnosis is uncertain – then a punch biopsy may be taken and sent for histopathology to assist in the diagnosis
Management
General advice
- Ensure clothing not too tight
- Ensure adequate personal hygiene – e.g. washing or showering shortly after exercise
- Try to avoid a high humidity environment under clothing
- Consider use of chlorhexidine body wash
- Shaving advice – avoid going “against the grain”
- Avoid towel sharing within households
- Ensure adequate sterilisation of hot tubs!
Medical and surgical management
Most cases of superficial Folliculitis are mild and will resolve with the above measures an no other specific treatment is required. In more severe cases, consider:
- Topical (e.g. mupirocin BD-TDS, or clindamycin) or oral antibiotics (e.g. flucloxacillin or cephalexin 250-500mg QID). Antibiotic choice may also be based on culture results
- Gram-negative Folliculitis may be treated with isotretinoin (like acne) – but beware the side effects – especially the risk of brith defects in women of reproductive age
- Very rarely deep infections might require incision and drainage
- Consider laser hair removal in stubborn or recurrent cases
References
- Murtagh’s General Practice. 6th Ed. (2015) John Murtagh, Jill Rosenblatt
- Beers, MH., Porter RS., Jones, TV., Kaplan JL., Berkwits, M. The Merck Manual of Diagnosis and Therapy
- Folliculitis – patient.info
- Folliculitis – dermnet
- Bacterial Folliculitis – dermnet
- Therapeutic Guidelines – Folliculitis