Folliculitis: Symptoms, Types, Causes and Treatment

Folliculitis is a common yet often misunderstood skin condition that affects people of all ages. At its core, folliculitis is an inflammation of the hair follicles, leading to a range of visible and sometimes uncomfortable symptoms. However, beneath this simple definition lies a complex world of causes, types, and treatment options. This article unpacks the details of folliculitis with a focus on evidence-based information, helping you understand what to look for, what may be causing your symptoms, and how best to address them.

Symptoms of Folliculitis

Folliculitis can manifest in various ways, often mimicking other skin conditions. Early recognition of its symptoms can help in timely management and prevent complications such as scarring or chronic infection. While the presentation can differ depending on the type and cause, certain key features are commonly observed.

Symptom	Description	Frequency/Severity	Source
Papules	Small, red, raised bumps around hair follicles	Acute/Very common	1 5 9
Pustules	Pus-filled lesions, often with a central hair	Acute/Common	1 5 9
Itching	Sensation of itch, sometimes intense	Variable	2 3 14
Pain/Burning	Discomfort, pain, or burning in affected areas	Sometimes present	2 14
Erythema	Redness and inflammation around follicles	Frequent	1 2 14
Crusting	Overlying crusts, especially in chronic cases	Seen in advanced forms	2 14
Hair Loss	Patchy or scarring alopecia in severe types	In chronic/severe cases	2 14 15

Table 1: Key Symptoms

Common Presentations

Folliculitis typically presents as small, red bumps (papules) or pus-filled lesions (pustules) centered around hair follicles. These lesions are often surrounded by a ring of redness (erythema), and may be accompanied by itching or a burning sensation. In some cases, especially with chronic or severe folliculitis, patients may notice crusts forming on the skin or even areas of hair loss if scarring occurs 1 2 14.

Variability of Symptoms

• Acute vs. Chronic: Acute folliculitis usually features tiny pustules or papulopustules, while chronic cases can lead to hyperkeratosis and scarring 1.
• Severity: The extent of symptoms can vary from mild irritation to large, thickly scarred areas, especially in forms like folliculitis decalvans 2 14 15.
• Location: Symptoms may appear anywhere with hair follicles but are most common on the scalp, face, trunk, and limbs 1 9.

Recognizing Special Features

• Tufted Folliculitis: Multiple hairs emerge from a single follicular opening, often in folliculitis decalvans, and may be associated with crusts or erosions 2 12 14.
• Itching and Pain: Itching is common and can be severe in eosinophilic pustular folliculitis, while pain or burning is more typical in advanced or inflamed lesions 2 3 14.

Types of Folliculitis

Folliculitis is not a one-size-fits-all diagnosis. There are numerous types, each with unique causes, clinical features, and potential complications. Understanding these distinctions is crucial for effective management.

Type	Key Features	Typical Location(s)	Source
Bacterial	Pustules, erythema, often S. aureus-related	Face, scalp, body	1 9 10
Fungal	Papules/pustules, may be itchy	Trunk, limbs	5 7
Viral	Rare, herpetic appearance	Face, genital area	5 10
Parasitic	Demodex/scabies, intense itch	Face, body	5 10
Folliculitis Decalvans	Scarring, tufted hairs, crusts	Scalp (vertex/occiput)	2 12 14
Eosinophilic	Sterile papules/pustules, severe itch	Face, trunk, arms	3 4 5
Pseudofolliculitis	Ingrown hairs, no infection	Beard, areas of shaving	1 5 9

Table 2: Types of Folliculitis

Infectious Folliculitis

Bacterial Folliculitis

The most common type, typically caused by Staphylococcus aureus, presents as groups of red, pus-filled bumps 1 9 10. Gram-negative bacteria, such as Pseudomonas (hot tub folliculitis), may also be culprits.

Fungal Folliculitis

Often caused by dermatophytes or yeast, fungal folliculitis creates itchy pustules and is more frequent in warm, moist conditions 5 7. Dermatophyte folliculitis (tinea barbae) is common in the beard area.

Viral and Parasitic Folliculitis

Less common, viral folliculitis may be seen with herpes simplex infections; parasitic forms (e.g., Demodex, scabies) present with intense itching and can be detected via dermoscopy 5 10.

Non-Infectious Folliculitis

Folliculitis Decalvans

A rare, chronic, scarring type most often affecting the scalp. Key features include pustules, crusts, tufted hair (multiple hairs from one follicle), and eventual hair loss 2 12 14. This form can be disfiguring and challenging to treat.

Eosinophilic Pustular Folliculitis

Characterized by recurrent, intensely itchy, sterile papules and pustules, this type often affects immunocompromised individuals, such as those with HIV/AIDS, but can also occur in otherwise healthy people 3 4 5.

Pseudofolliculitis

Not a true infection, but rather an inflammatory reaction to ingrown hairs, commonly seen in the beard area (pseudofolliculitis barbae) or other areas subjected to shaving or friction 1 5 9.

Causes of Folliculitis

Folliculitis arises from a variety of triggers, both infectious and non-infectious. Understanding the underlying cause is essential for targeting treatment and preventing recurrence.

Cause	Explanation	Typical Triggers	Source
Bacteria	S. aureus, Gram-negative organisms	Skin trauma, immunosuppression	1 9 10 14
Fungi	Dermatophytes, Malassezia species	Warmth, humidity	5 7
Viruses	Herpes simplex	Immunosuppression	5 10
Parasites	Demodex, scabies	Close contact, poor hygiene	5 10
Autoimmune/Immune	Eosinophilic infiltration, abnormal response	HIV/AIDS, idiopathic	3 4 6
Mechanical/Irritant	Shaving, friction, occlusion	Razors, tight clothing	1 5 9
Drugs	EGFR inhibitors, corticosteroids	Cancer therapy, long-term steroids	13
Unknown	Idiopathic (esp. in chronic forms)	N/A	2 14

Table 3: Causes of Folliculitis

Infectious Causes

• Bacteria: Staphylococcus aureus is the leading bacterial cause, but Gram-negative bacteria and even Propionibacterium acnes can be implicated 1 9 10 14.
• Fungi: Dermatophytes and yeasts (like Malassezia) thrive in warm, moist environments, leading to follicular inflammation 5 7.
• Viruses and Parasites: Herpes simplex virus may occasionally cause folliculitis, as can scabies mites or Demodex species 5 10.

Non-Infectious Causes

• Immune-Mediated: Eosinophilic pustular folliculitis appears to be related to immune dysregulation, especially in those with HIV/AIDS or other immunodeficiencies 3 4 6.
• Mechanical/Irritant: Shaving, tight clothing, and friction can cause trauma to hair follicles, leading to pseudofolliculitis or irritant folliculitis 1 5 9.
• Drug-Induced: Certain medications, notably EGFR inhibitors used in cancer therapy, are well-documented causes of drug-induced folliculitis 13.

Other Contributing Factors

• Skin Barrier Dysfunction: Any factor that impairs the skin's protective barrier increases susceptibility to folliculitis 8 14.
• Host Immune Status: People with compromised immunity (e.g., diabetes, HIV) are at higher risk for both infectious and non-infectious folliculitis 4 6 13.

Treatment of Folliculitis

Effective treatment of folliculitis depends on identifying the type and underlying cause. Management strategies range from simple self-care to advanced medical therapies, especially in chronic or severe cases.

Treatment	Indication	Notes	Source
Topical Antibiotics	Mild bacterial folliculitis	Mupirocin, clindamycin	1 9 10
Systemic Antibiotics	Extensive/severe bacterial cases	Cephalexin, tetracyclines, rifampicin/clindamycin	12 14 15
Antifungals	Fungal folliculitis	Topical or oral azoles	5 7
Antivirals	Viral folliculitis (rare)	Acyclovir (HSV)	5 10
Anti-parasitics	Parasitic folliculitis	Permethrin, ivermectin	5 10
Topical Steroids	Inflammatory/non-infectious types	Use with care	1 14 15
Immunomodulators	Eosinophilic or autoimmune forms	Dapsone, phototherapy	3 4
Drug Cessation	Drug-induced folliculitis	EGFRI withdrawal if possible	13
Preventive Care	Hygiene, shaving technique, avoid irritants	Crucial for recurrence	1 5 9

Table 4: Treatment Options

General Principles

• Identify and Treat the Cause: Effective management hinges on accurate diagnosis, which may involve cytology, cultures, or even biopsy in atypical cases 10.
• Hygiene and Prevention: Good skin hygiene, proper shaving techniques, and avoidance of irritants can prevent many cases and recurrences 1 5 9.

Medical Therapies

Bacterial Folliculitis

• Topical antibiotics are first-line for localized, mild cases.
• Systemic antibiotics (such as cephalexin, tetracyclines, or a combination of rifampicin and clindamycin) are reserved for severe, widespread, or chronic forms, especially folliculitis decalvans 12 14 15.
• Treatment of folliculitis decalvans may require prolonged courses and can be challenging due to its chronic, relapsing nature 14 15.

Fungal, Viral, and Parasitic Folliculitis

• Antifungals (topical or oral) are used for confirmed fungal cases 5 7.
• Antivirals are rarely needed, but may be used for herpetic folliculitis 5 10.
• Anti-parasitic agents (permethrin, ivermectin) are effective for parasitic folliculitis 5 10.

Non-Infectious and Drug-Induced Types

• Eosinophilic folliculitis may respond to topical steroids, dapsone, or phototherapy. Management of underlying immunodeficiency is crucial 3 4.
• Drug-induced folliculitis: Prophylactic tetracyclines are recommended for patients on EGFR inhibitors, with curative benefit less well-established 13.

Other Interventions

• Intralesional steroids may help in resistant or severe inflammatory cases 14 15.
• Immunomodulators (such as dapsone) or phototherapy are considered for recalcitrant eosinophilic folliculitis 3 4.
• Restoration of Microbiota: For chronic forms like folliculitis decalvans, emerging research suggests that restoring normal skin microbiota may offer new treatment avenues 8.

Conclusion

Folliculitis is a multifaceted condition with diverse types, triggers, and management strategies. Understanding these differences is key to effective care and prevention.

Key Takeaways:

• Folliculitis presents primarily as papules, pustules, redness, and sometimes discomfort or itching; chronic forms may lead to scarring and hair loss.
• Types of folliculitis include infectious (bacterial, fungal, viral, parasitic) and non-infectious forms (folliculitis decalvans, eosinophilic, pseudofolliculitis).
• Causes range from microbial invasion and immune dysfunction to mechanical irritation and drug reactions.
• Treatment must be tailored to the underlying cause, with options including topical or systemic antibiotics, antifungals, antivirals, anti-parasitics, steroids, and immunomodulators.
• Preventive care and addressing underlying risk factors are crucial for minimizing recurrences and complications.

If you suspect you have folliculitis, or if your symptoms are persistent, severe, or associated with hair loss, consult a dermatologist for accurate diagnosis and targeted therapy.