Folliculitis is an infectious lesion of the middle and deep parts of the hair follicle, leading to its purulent inflammation. Disease can have bacterial, fungal, viral, parasitic etiology. It manifests itself by the appearance of single or multiple pustules in the places of hair growth, along the center of which the hair passes. The opened pustules form ulcers, their healing with a deep lesion of the hair follicle is accompanied by scarring. Diagnosis is carried out by dermatoscopy, smear microscopy and examination of the separated pustules. Treatment is carried out with solutions of aniline dyes, antiseptic agents, local and systemic use of etiotropic drugs: antibiotics, antimycotics, acyclovir.
Along with hydradenitis, sycosis, streptoderma and streptococcal impetigo, folliculitis refers to purulent skin diseases (pyoderma), the prevalence of which among the population reaches 40%. In hot countries, the incidence of folliculitis is higher, since the climate itself contributes to the development of infection. A high level of morbidity is also noted among socially disadvantaged segments of the population living in unsanitary conditions.
In some cases, disease begins with ostiofolliculitis — a superficial inflammation of the hair follicle, affecting only its mouth. Further spread of infection into the depth of the follicle leads to the transformation of ostiofolliculitis into folliculitis.
Infectious agents that cause folliculitis, in most cases, are bacteria, mainly staphylococci. There are folliculitis caused by pseudomonads, the causative agent of syphilis, gonorrhea, etc. bacteria. The cause of the disease can be fungal skin lesions (fungi of the genus Candida and Pityrosporum, dermatophytes), viruses (contagious mollusc, herpes simplex and herpes zoster) and parasites (for example, a tick that causes demodecosis). In accordance with the etiology of the infectious process, clinical dermatology distinguishes bacterial, fungal, viral, syphilitic and parasitic folliculitis.
The penetration of infection into the hair follicle occurs through minor skin damage: scratches, excoriation, abrasions, wetness. The probability of infection is increased in people suffering from itchy dermatoses (eczema, pruritus, atopic dermatitis, allergic contact dermatitis, During dermatitis) and therefore constantly combing their skin, as well as in people suffering from excessive sweating.
The weakening of the body’s defenses and the barrier function of the skin facilitates the penetration of infection into the hair follicle and the development of folliculitis. Therefore, factors contributing to infection include diabetes mellitus and various immunodeficiencies: HIV infection, conditions associated with a long-term illness or immunosuppressive therapy. Prolonged cutaneous use of glucocorticosteroids leads to a decrease in local immunity and may also favor the development of folliculitis. A decrease in the protective properties of the skin also occurs with prolonged exposure to various chemicals: kerosene, lubricants, technical oils. These are associated with the occurrence of professional folliculitis in locksmiths, tractor drivers, oil workers.
Folliculitis begins with redness and infiltration in the area of the hair follicle. Then a conical pustule with purulent contents in the center permeated with fluffy hair is formed. After its opening and release from pus, a small ulcer is formed, covered with a bloody-purulent crust. When the entire follicle is affected, hyperpigmentation or scar remains on the skin after the peel is removed. More superficial form can resolve without leaving any traces behind. The process of development and resolution of inflammation of one follicle takes up to 1 week.
Most often, folliculitis is of a multiple nature. Its elements are usually located on hairy areas of the skin: on the face, head, armpits, groin, legs (mainly in women depilating the lower legs and thighs). Rashes are accompanied by soreness and itching of varying severity. In the absence of proper treatment and hygienic measures, folliculitis is complicated by the development of a boil, carbuncle, hydradenitis, abscess, phlegmon.
Staphylococcal folliculitis is usually localized in the areas of growth of bristly hair, most often it is the chin and the skin around the mouth. It is found mainly in men who shave their beard and mustache. It may be complicated by the development of sycosis.
Pseudomonas folliculitis is popularly called “hot bath folliculitis”, because in most cases it occurs after taking a hot bath with insufficient chlorination of water. It often develops in patients undergoing antibiotic therapy for acne. Clinically expressed in a sharp increase in acne, the appearance of hair-permeated pustules on the face and upper body.
Syphilitic folliculitis (acne-like syphilis) develops with secondary syphilis, accompanied by non-pubic alopecia in the growth zone of the beard and mustache, as well as the scalp.
Gonorrheal folliculitis is a complication of untreated and long-lasting gonorrhea. A favorite localization is the skin of the perineum in women and the foreskin in men.
Candidiasis folliculitis is observed mainly when occlusive dressings are applied, in bedridden patients and with prolonged fever.
Dermatophytic folliculitis is characterized by the onset of inflammatory changes from the superficial stratum corneum of the epidermis. Then the process gradually captures the follicle and the hair shaft. It can occur against the background of favus, leaving behind scarring.
Herpetic folliculitis is characterized by the formation of vesicles in the mouths of hair follicles. It is observed on the skin of the chin and nasolabial triangle, more often in men.
Folliculitis caused by demodecosis is manifested by redness of the skin with the formation of characteristic pustules in the mouths of the hair follicles, around which there is a bran-like peeling.
Bockhart’s impetigo is another variant of folliculitis. It develops during maceration of the skin. It is most often found with hyperhidrosis or as a result of therapy with warming compresses.
Diagnostic measures in case of suspected folliculitis are aimed at studying the condition of the hair follicle; determining the pathogen that caused inflammation; excluding the specific etiology of the disease (syphilis, gonorrhea); identifying concomitant diseases that favor the development of the infectious process.
At the consultation of a dermatologist, an examination of rashes and dermatoscopy is performed, which helps the doctor determine the depth of the lesion of the follicle. The separated pustules are taken for microscopy and bacteriological seeding, studies for fungi and pale treponema. To exclude gonorrhea and syphilis, PCR diagnostics and an RPR test are performed. If necessary, the patient is prescribed an immunogram, a blood sugar test and other examinations.
During the diagnosis, folliculitis is differentiated from ostiofolliculitis, phrynoderma, Hoffmann’s perifolliculitis, furunculosis, nodular cystic acne, streptococcal impetigo, pink lichen of Gibert, drug toxicoderma.
Treatment of folliculitis should correspond to its etiology. With bacterial genesis of folliculitis, ointments with antibiotics are prescribed, with fungal — antifungal drugs, treatment of herpetic folliculitis is carried out with acyclovir.
At the beginning of the disease, local therapy and treatment of lesions with solutions of aniline dyes (fucarcin, zelenka, methylene blue) are sufficient. To prevent the spread of infection to healthy areas of the skin, they are treated with salicylic or boric alcohol. Additionally, the UVI is used.
Cases of severe recurrent course of folliculitis require systemic therapy. With staphylococcal folliculitis, cephalexin, dicloxacillin, erythromycin are prescribed inside. Treatment of severe forms of pseudomonasal folliculitis is carried out with ciprofloxacin. With candidiasis folliculitis, fluconazole and itraconazole are used, with dermatophytic — terbinafine. At the same time, concomitant diabetes mellitus or immunodeficiency conditions are being treated.