Folliculitis is the infection and

inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

of one or more

hair follicle The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction betwee ...

s. The condition may occur anywhere on hair-covered

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different ...

. The rash may appear as

pimple A pimple or zit is a kind of comedo that results from excess sebum and dead skin cells getting trapped in the pores of the skin. In its aggravated state, it may evolve into a pustule or papule. Pimples can be treated by acne medications, anti ...

s that come to white tips on the face, chest, back, arms, legs, buttocks, or head. Although

acne Acne ( ), also known as ''acne vulgaris'', is a long-term Cutaneous condition, skin condition that occurs when Keratinocyte, dead skin cells and Sebum, oil from the skin clog hair follicles. Typical features of the condition include comedo, ...

can often involve superficial infection and inflammation of some hair follicles, the condition of those follicles is usually not called folliculitis, as that term is usually reserved for the separate set of disease entities comprising infected and inflamed hair follicles with causes other than acne.

Signs and symptoms

Histopathology of granulomatous folliculitis

Rash A rash is a change of the skin that affects its color, appearance, or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracke ...

(reddened skin area) *

Itch An itch (also known as pruritus) is a sensation that causes a strong desire or reflex to scratch. Itches have resisted many attempts to be classified as any one type of sensory experience. Itches have many similarities to pain, and while both ...

ing skin *

Pimple A pimple or zit is a kind of comedo that results from excess sebum and dead skin cells getting trapped in the pores of the skin. In its aggravated state, it may evolve into a pustule or papule. Pimples can be treated by acne medications, anti ...

s or

pustule A skin condition, also known as cutaneous condition, is any medical condition that affects the integumentary system—the organ system that encloses the body and includes skin, nails, and related muscle and glands. The major function of this ...

s located around a hair or follicle; may be confused with

chicken pox Chickenpox, also known as varicella ( ), is a highly contagious disease caused by varicella zoster virus (VZV), a member of the herpesvirus family. The disease results in a characteristic skin rash that forms small, itchy blisters, which ...

** May crust over ** Typically occur on neck,

armpit The axilla (: axillae or axillas; also known as the armpit, underarm or oxter) is the area on the human body directly under the shoulder joint. It includes the axillary space, an anatomical space within the shoulder girdle between the arm an ...

, or

groin In human anatomy, the groin, also known as the inguinal region or iliac region, is the junctional area between the torso and the thigh. The groin is at the front of the body on either side of the pubic tubercle, where the lower part of the abdom ...

** May present as

genital A sex organ, also known as a reproductive organ, is a part of an organism that is involved in sexual reproduction. Sex organs constitute the primary sex characteristics of an organism. Sex organs are responsible for producing and transporting ...

lesion A lesion is any damage or abnormal change in the tissue of an organism, usually caused by injury or diseases. The term ''Lesion'' is derived from the Latin meaning "injury". Lesions may occur in both plants and animals. Types There is no de ...

s * Spreading from leg to arm to body through improper treatment with antibiotics File:Sebaceaous Hyperplasia Chronic folliculits Right Mid Chest.jpg, Chronic folliculitis surrounding central sebaceous hyperplasia, right mid-chest

Complications

This condition can develop into a more severe skin condition, such as

cellulitis Cellulitis is usually a bacterial infection involving the inner layers of the skin. It specifically affects the dermis and subcutaneous fat. Signs and symptoms include an area of redness which increases in size over a few days. The borders of ...

abscess An abscess is a collection of pus that has built up within the tissue of the body, usually caused by bacterial infection. Signs and symptoms of abscesses include redness, pain, warmth, and swelling. The swelling may feel fluid-filled when pre ...

Causes

Most

carbuncle A carbuncle is a cluster of boils caused by bacterial infection, most commonly with ''Staphylococcus aureus'' or ''Streptococcus pyogenes''. The presence of a carbuncle is a sign that the immune system is active and fighting the infection. The ...

boil A boil, also called a furuncle, is a deep folliculitis, which is an infection of the hair follicle. It is most commonly caused by infection by the bacterium ''Staphylococcus aureus'', resulting in a painful swollen area on the skin caused by ...

s, and other cases of folliculitis are infected with ''

Staphylococcus aureus ''Staphylococcus aureus'' is a Gram-positive spherically shaped bacterium, a member of the Bacillota, and is a usual member of the microbiota of the body, frequently found in the upper respiratory tract and on the skin. It is often posi ...

''. Folliculitis starts with the introduction of a skin

pathogen In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a Germ theory of d ...

to a hair follicle. Hair follicles can also be damaged by

friction Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal -- an incomplete list. The study of t ...

from

clothing Clothing (also known as clothes, garments, dress, apparel, or attire) is any item worn on a human human body, body. Typically, clothing is made of fabrics or textiles, but over time it has included garments made from animal skin and other thin s ...

, an insect bite, blockage of the follicle,

shaving Shaving is the removal of hair, by using a razor or any other kind of bladed implement, to slice it down—to the level of the skin or otherwise. Shaving is most commonly practiced by men to remove their facial hair and by women to remove the ...

, or

braids A braid (also referred to as a plait; ) is a complex structure or pattern formed by interlacing three or more strands of flexible material such as textile yarns, wire, or hair. The simplest and most common version is a flat, solid, three-strand ...

that are very tight and close to the scalp. The damaged follicles are then infected by ''Staphylococcus'' spp. Folliculitis can affect people of all ages.

Iron-deficiency anemia Iron-deficiency anemia is anemia caused by a iron deficiency, lack of iron. Anemia is defined as a decrease in the number of red blood cells or the amount of hemoglobin in the blood. When onset is slow, symptoms are often vague such as Fatigue ( ...

is sometimes associated with chronic cases.

Bacterial

* ''Staphylococcus aureus'' folliculitis *

Hot-tub folliculitis Hot tub folliculitis, also called ''Pseudomonal'' folliculitis or Pseudomonas aeruginosa folliculitis, is a common type of folliculitis featuring inflammation of hair follicles and surrounding skin. This condition is caused by an infection of the ...

is caused by the bacterium ''

Pseudomonas aeruginosa ''Pseudomonas aeruginosa'' is a common Bacterial capsule, encapsulated, Gram-negative bacteria, Gram-negative, Aerobic organism, aerobic–facultative anaerobe, facultatively anaerobic, Bacillus (shape), rod-shaped bacteria, bacterium that can c ...

''. The folliculitis usually occurs after sitting in a hot tub that was not properly cleaned before use. Symptoms are found around the body parts that sit in the hot tub – the legs, hips, chest,

buttocks The buttocks (: buttock) are two rounded portions of the exterior anatomy of most mammals, located on the posterior of the pelvic region. In humans, the buttocks are located between the lower back and the perineum. They are composed of a lay ...

, and surrounding areas. Symptoms are amplified around regions that were covered by wet clothing, such as

bathing suit A swimsuit is an item of clothing designed to be worn by people engaging in a water-based activity or water sports, such as swimming, diving and surfing, or sun-orientated activities, such as sun bathing. Different types and styles may be worn ...

s. * Sycosis vulgaris, sycosis barbae, or barber's itch is a staphylococcal infection of the hair follicles in the bearded area of the face, usually the upper lip. Shaving aggravates the condition. * Gram-negative folliculitis may appear after prolonged acne treatment with antibiotics.

Fungal

Tinea barbae Tinea barbae is a fungal infection of the hair. Tinea barbae is due to a dermatophyte, dermatophytic infection around the bearded area of men. Generally, the infection occurs as a follicular inflammation, or as a cutaneous granulomatous lesion, i.e ...

is similar to barber's itch, but the infection is caused by the

fungus A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

'' T. rubrum''. * Malassezia folliculitis, formerly known as ''Pityrosporum ''folliculitis, is caused by yeasts (part of the fungus kingdom) of the genus ''

Malassezia ''Malassezia'' is a genus of fungi (specifically, a yeast belonging to the division Basidiomycota). Some species of ''Malassezia'' are found on the skin of animals, including humans. Because malassezia requires fat to grow, it is most common in ...

Mites

* Demodex folliculitis is usually caused by an overgrowth of ''

Demodex folliculorum ''Demodex folliculorum'' is a microscopic mite that can survive only on the skin of humans. Most people host ''D.folliculorum'' on their skin particularly on the face, where sebaceous glands are most concentrated. Usually, the mites do not caus ...

'', a mite that lives in human hair follicles. Although most people with ''D. folliculorurm'' have no symptoms, the mite can reproduce excessively, particularly in people with oily scalps.

Viral

* Herpetic folliculitis is rarer, but may occur when

herpes simplex virus Herpes simplex virus 1 and 2 (HSV-1 and HSV-2) are two members of the Herpesviridae#Human herpesvirus types, human ''Herpesviridae'' family, a set of viruses that produce Viral disease, viral infections in the majority of humans. Both HSV-1 a ...

infection spreads to nearby hair follicles appearing in groups or clusters, mostly around the mouth.

Noninfectious

* Pseudofolliculitis barbae is a disorder occurring when hair curves back into the skin and causes inflammation. * Eosinophilic folliculitis may appear in persons with impaired immune systems. * Folliculitis decalvans or tufted folliculitis usually affects the scalp. Several hairs arise from the same hair follicle. Scarring and permanent hair loss may follow. The cause is unknown. *

Folliculitis keloidalis Folliculitis is the infection and inflammation of one or more hair follicles. The condition may occur anywhere on hair-covered skin. The rash may appear as pimples that come to white tips on the face, chest, back, arms, legs, buttocks, or head. A ...

scarring on the nape of the neck is most common among males with curly hair. * Oil folliculitis is inflammation of hair follicles due to exposure to various oils, and typically occurs on forearms or thighs. It is common in refinery workers, road workers, mechanics, and sheep shearers. Even makeup may cause it. * Malignancy may also be represented by recalcitrant cases.Folliculitis, follicular mucinosis, and papular mucinosis as a presentation of chronic myelomonocytic leukemia. Rashid R, Hymes S. Dermatol Online J. 2009 May 15;15(5):16.

Treatment

Most simple cases resolve on their own, but first-line treatments are typically topical medications. # Topical

antiseptic An antiseptic ( and ) is an antimicrobial substance or compound that is applied to living tissue to reduce the possibility of sepsis, infection, or putrefaction. Antiseptics are generally distinguished from ''antibiotics'' by the latter's abil ...

treatment is adequate for most cases. # Topical

antibiotic An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...

s, such as

mupirocin Mupirocin, sold under the brand name Bactroban among others, is a topical antibiotic useful against superficial skin infections such as impetigo or folliculitis. It may also be used to get rid of methicillin-resistant ''S. aureus'' (MRSA) wh ...

neomycin/polymyxin B/bacitracin Neomycin/polymyxin B/bacitracin, also known as triple antibiotic ointment, and sold under the brand name Neosporin, among others, is an antibiotic medication used to reduce the risk of cellulitis, infections following minor skin injuries. It c ...

ointment may be prescribed. Oral antibiotics may also be used. # Some patients may benefit from systemic narrow-spectrum penicillinase-resistant penicillins (such as

dicloxacillin Dicloxacillin is a narrow-spectrum β-lactam antibiotic of the penicillin class. It is used to treat infections caused by susceptible (non-resistant) Gram-positive bacteria.Product Information: DICLOXACILLIN SODIUM-dicloxacillin sodium capsule. ...

in the US or

flucloxacillin Flucloxacillin, also known as floxacillin, is an antibiotic used to treat skin infections, external ear infections, infections of leg ulcers, diabetic foot infections, and infection of bone. It may be used together with other medications to ...

in UK). # Fungal folliculitis may require an oral antifungal such as

fluconazole Fluconazole is an antifungal medication used for a number of fungal infections. These include candidiasis, blastomycosis, coccidioidomycosis, cryptococcosis, histoplasmosis, dermatophytosis, and tinea versicolor. It is also used to pr ...

. Topical antifungals such as econazole nitrate may also be effective. Folliculitis may recur even after symptoms have gone away.

References

External links

Malassezia (Pityrosporum) Folliculitis Treatment & Management
{{Bacterial cutaneous infections Conditions of the skin appendages Bacterium-related cutaneous conditions Dermal and subcutaneous growths