Folliculitis decalvans can affect any hair follicle in the body, although it is generally limited to the scalp, where it spreads in a coronal pattern. It rarely involves hair on the legs, arms, thighs and in the face, axilla and in the public areas. It manifests in a circular or oval pattern. Pustules generally surround hair follicles and are called perifollicular pustules. A distinctive characteristic of the condition is the presence of many hairs in a single follicle. The scalp in this takes the appearance of a tuft, resembling a toothbrush. Scarring can occur when the hair falls off and the follicle is destroyed due to scarring.

Patients can be either men or women. Male patients tend to be younger, with most female patients presenting after their fourth decade. The condition nonetheless does not affect individuals before adolescence. Prominent symptoms include pain, tightness, and itching. Some patients, nonetheless, may not report any discomfort.

The disease, in general, is limited, but complications may rarely occur, in which there is an extensive spread of the hair loss in the scalp.

• Alopecia

  Alopecias can be categorized as nonscarring or scarring. Nonscarring alopecias include male and female pattern alopecias, alopecia areata, telogen effluvium, traction alopecia, trichotillomania, and tinea capitis. [unboundmedicine.com]

  Definition / general Alopecia: hair loss from head or body Folliculitis decalvans: alopecia that involves scarring; redness, swelling and pustules around hair follicle, with subsequent follicular destruction and permanent hair loss Diagnosis Adequate [pathologyoutlines.com]

  Figure 3 Trichoscopy showing follicular tufts, pustules and dilated blood vessels in an area of scarring alopecia. [dovepress.com]

  Folliculitis decalvans, first described by Quinquaud in 1888, is the most common form of the neutrophilic primary cicatricial alopecia. [taylorfrancis.com]

  “A new look at scarring alopecia”. Arch Dermatol. vol. 136. 2000. pp. 235-42. (A seminal article on new categories for scarring alopecia.) Stefanato, C. “Histopathology of alopecia: a clinicopathological approach to diagnosis”. [dermatologyadvisor.com]

• Scalp Rash

  On DermNet NZ: Hair loss Folliculitis Diagnosis of scalp rashes Melanoma in skin of colour Other websites: Cicatricial Alopecia Research Foundation Tufted hair folliculitis – Medscape Drugs & Diseases Folliculitis decalvans – British Association of Dermatologists [dermnetnz.org]

• Tenderness of the Scalp

  FD may cause itching, inflammation, tenderness, tight feeling scalp, and, rarely, you may have no symptoms at all. Unlike genetic hair loss in which you might only experience hair thinning, FD also includes inflammatory symptoms. [healthline.com]

• Neglect

  Patient 11 [Figures 1–3] needed combinations of different antimicrobials with aggressive adjuvant therapy, as he neglected treatment in the beginning and his condition worsened significantly with scalp scarring. [ncbi.nlm.nih.gov]

Workup includes a biopsy of the skin in the area affected by the disease. In addition to a biopsy, cultures of the exudates and hair specimen can be helpful in determining the antibiotic sensitivity and improving treatment options. Fungi are generally not present in the lesions. Their detection should prompt the physician to consider another diagnosis. The patient does not require in most cases extensive laboratory testing.

Histopathological analysis is the most important component of the workup. Prominent findings include increased keratosis, hyperplasia of the dermis, parakeratosis, and plugging of the follicles. Inflammatory cells can also be found, especially neutrophils, plasma cells, and lymphocytes, which are usually present in the upper reticular and papillary portions of the dermis. Fragments of hair can be detected within giant cells, especially where rupture of the follicles occurred. On the other hand, tufting areas exhibit a thinning of the sheath of the infundibulum, with changes in the spaces that separate adjacent hairs. This will ultimately result in fusion of the upper follicular divisions. Characteristic features on histology also include the presence of many hairs within a single follicle and large quantities of telogen hairs within the tufts.

The dermis and subcutis are generally intact in folliculitis decalvans, with normal anagen hair bulbs. Histology of tufted and scarred areas resulting from other disease mechanisms will reflect other primary causes.

It is important to note that histology alone is not sufficient to establish a diagnosis. The overall clinical picture, histology, and bacterial cultures should be used in combination to determine the cause of the symptoms.

Treatment of folliculitis decalvans can be subdivided into primary and secondary. Primary care is aimed at eradicating staphylococcus aureus. Secondary care is directed at the complications of the conditions, such as scarring, and consists of rifampicin, clindamycin and occasionally isotretinoin. In rare cases, excision of small areas of folliculitis decalvans can be done.

Folliculitis decalvans follows a chronic course with multiple episodes of remission and recurrence. Morbidity and complications are generally limited to localized discomfort and aesthetic worries.

Folliculitis decalvans is part of a spectrum of diseases related to scarring alopecia and is not a unique entity. It represents an advanced stage of the condition, in which there is considerable damage to hair follicles. The etiological mechanisms underlying folliculitis decalvans remain unknown and most cases are thought to be idiopathic. Nonetheless, several theories have been proposed to explain the mechanisms underlying the disease.

The most popular theory was proposed by Smith and Anderson in the first report related to the disease. They suggested that, following severe damage to the upper part of the follicle, follicular epithelium grows around the hair shafts [3]. Nowadays, many authors support the basic claims of this theory but suggest some variations. They claim that inflammation within the papillary and upper reticular components of the dermis leads to a contraction of interfollicular dermal tissue. This, in turn, causes different follicles to fuse and tufts to form.

Tufting is further exacerbated by inflammation around the follicles which maintains the presence of telogen hairs. Other researchers claim that nevoid malformation is the representation of tuft formation [4].

Staphylococcus aureus (S. aureus) can be cultured in the majority of cases of folliculitis, although the exact role of the bacterium remains unknown. It is thought that invasion with S. aureus occurs after the initial stages of the diseases and can contribute to its progression. Nonetheless, some maintain that infection with S. aureus is the primary cause, with toxins released by the bacterium leading to severe inflammation in the superior dermis, with ultimate scarring of the tissue.

Folliculitis decalvans has been also associated with medication intake, in particular, lapatinib and cyclosporin [5] [6]. The pathophysiological mechanisms involved have not been elucidated and the incidence of drug-associated folliculitis decalvans remains rare.

Other disorders and conditions that were associated with folliculitis decalvans include acne keloidalis, dissecting cellulitis of the scalp, Melkersson-Rosenthal syndrome, pemphigus vulgaris, hidradenitis suppurativa, scars following trauma or surgery and lichen planus [2] [7] [8] [9] [10].

Folliculitis decalvans occurs rarely both in the United States and internationally. No mortalities have ever been reported in direct association with the condition. Patients, nonetheless, suffer from local discomfort and loss of hair that can be cosmetically problematic. Folliculitis decalvans has no racial or gender predilection and has only been described in adult patients, most of them in their fourth and fifth decades.

The pathophysiological mechanisms of the condition have been mostly inferred from histopathological analyses. They demonstrate confluence of follicular infundibula, in addition to the presence of many hairs arising from a single follicle. The scarring process generally does not reach the lower parts of the hair follicle. Cultures can show infection with staphylococcus bacteria, although their role in the disease process has not been completely elucidated [11].

There are no current preventive measures for folliculitis decalvans.

Folliculitis decalvans is a medical condition that can ultimately result in scarring and hair loss [1]. It is characterized by inflammation of the hair follicle and the formation of hair tufts. The underlying pathophysiological mechanisms are still not well understood. Infection of the lesions with staphylococcus aureus is common and it is thought that the organism may participate in initiating the disease or at least in exacerbating progression. Patients usually present with localized discomfort, itching, redness and sometimes pain. The condition has a distinctive appearance of hair tufts, resembling toothbrushes or doll hair. This is caused by the fact that multiple hairs can arise from a single follicle because of underlying inflammatory processes that decrease the space between adjacent hair cells. The condition may then complicate with scarring and permanent hair loss. Folliculitis decalvans has no absolute cure but treatment options exist that can potentially limit scarring. The goal of primary treatment is to eradicate infections with staphylococcus aureus while secondary treatment with rifampicin, clindamycin or isotretinoin helps in limiting scarring. Recurrence is rare but can occur if treatment is not continued [2].

Folliculitis decalvans is considered as a primary cicatricial alopecia. Primary cicatricial alopecias are a group of disorders characterized by inflammation that progressively destroy follicles and ultimately result in permanent hair loss. Secondary cicatricial alopecia, on the other hand, results from skin scarring that incidentally destroys follicles. Other classification systems categorize folliculitis decalvans as a neutrophilic cicatricial alopecia. This system was devised by the North American Hair Research Society and is based on the type of inflammatory cells associated with the disorder. The nomenclature of the disease was first devised by Brocq in 1905 but diagnostic criteria were not established until decades later.

Folliculitis decalvans is a skin disease that affects hair follicles generally, and the scalp more specifically. It is associated with inflammation and subsequent scarring. The term "folliculitis decalvans" is latin in origin and refers to inflammation of hair follicles in association with hair loss. The condition cannot be transmitted from person to person and does not involve any malignancy.The underlying cause of folliculitis decalvans remains unknown, although several theories have been proposed. One theory postulates that it is due to an inflammatory reaction subsequent to an infection with a bacterium called S. aureus. This bacteria can be normally present on the skin and does not necessarily lead to pathological manifestations. Folliculitis decalvans cannot be transmitted in a hereditary way, although some scientific reports indicate a higher frequency within certain families.

The underlying cause of folliculitis decalvans remains unknown, although several theories have been proposed. One theory postulates that it is due to an inflammatory reaction subsequent to an infection with a bacterium called S. aureus. This bacteria can be normally present on the skin and does not necessarily lead to pathological manifestations. Folliculitis decalvans cannot be transmitted in a hereditary way, although some scientific reports indicate a higher frequency within certain families.Folliculitis decalvans presents with local itching, discomfort, tightness and sometimes pain. Nonetheless, some patients may not exhibit any discomfort. Regions of the scalp affected by the disease may swell and redden, with areas of crusting and scabbing. Spots that contain pus can arise more frequently in the back of the head, although other areas of the scalp can also be involved. Scarring is the end result and a characteristic manifestation of the condition is the presence of several shafts of hair within the same follicle. This can give the distinctive appearance of "tufts of hair" that resemble a toothbrush or dolls-hair. The disease may lead eventually to patches with loss of hair that progressively increase in size. The phenomenon is termed 'cicatricial alopecia' in scientific parlance.

Folliculitis decalvans presents with local itching, discomfort, tightness and sometimes pain. Nonetheless, some patients may not exhibit any discomfort. Regions of the scalp affected by the disease may swell and redden, with areas of crusting and scabbing. Spots that contain pus can arise more frequently in the back of the head, although other areas of the scalp can also be involved. Scarring is the end result and a characteristic manifestation of the condition is the presence of several shafts of hair within the same follicle. This can give the distinctive appearance of "tufts of hair" that resemble a toothbrush or doll hair. The disease may lead eventually to patches with loss of hair that progressively increase in size. The phenomenon is termed 'cicatricial alopecia' in scientific parlance.

A dermatologist generally makes the diagnosis of folliculitis decalvans after a thorough skin exam and after taking samples for bacterial cultures. This is done by using a cotton wool bud and scraping the affected area. Cultures generally show infection with S. aureus, although this is not always the case. The presence of fungi should also be assessed, as similar fungal infections like ringworm can ultimately cause similar symptoms. Plucked hair may also be sent for sampling.

A skin biopsy is critical for diagnosis. This is achieved by taking a skin sample and sending it for examination by experts in histology and pathology. The procedure requires injection with a local anesthetic and an open incision that is closed with stitches. A small scar may be apparent after the wound heals.

There is no complete cure for folliculitis decalvans although treatment can control the associated symptoms. Scarring of hair follicles may lead to permanent hair loss, and its prevention is the main goal of treatment. Available treatment modalities include tablets, creams, shampoo and scalp solutions, in addition to antibiotics and topical steroids. Treatments that are more specific to the condition are not available. This is due to the absence of any specific trials for the disease due to its rarity, although some small case reports have been published. The condition requires most often long-term treatment because of risks for recurrence.

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