Folliculitis decalvans is an

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 the

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 ...

that leads to bogginess or

induration 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 sys ...

of involved parts of the scalp along with pustules, erosions, crusts, ulcers, and scale.Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicine''. (6th ed.). McGraw-Hill. .James, William; Berger, Timothy; Elston, Dirk (2005). ''Andrews' Diseases of the Skin: Clinical Dermatology''. (10th ed.). Saunders. . It begins at a central point and spreads outward, leaving scarring, sores, and, due to the inflammation, hair loss in its wake. No permanent cure has been found for this condition, but there is promise in a regimen of dual therapy with

rifampin Rifampicin, also known as rifampin, is an ansamycin antibiotic used to treat several types of bacterial infections, including tuberculosis (TB), ''Mycobacterium avium'' complex, leprosy, and Legionnaires' disease. It is almost always used tog ...

300 mg twice daily and clindamycin 300 mg twice daily. This treatment can be used to control the condition, and tests have indicated that after 3 to 5 months long uninterrupted courses of treatment, many patients have seen limited to no recurrence.

Causes

There is no certainty about the cause of this disorder, but the bacterial species ''

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 ...

'' has a central role and can be detected in the lesions of most patients. It is unclear if another primarily sterile process with secondary colonization by ''Staphylococcus aureus'' is present, or if Staphylococcus aureus starts the process by causing a strong immune reaction. Another possibility is that ''Staphylococcus aureus'' produces

toxin A toxin is a naturally occurring poison produced by metabolic activities of living cells or organisms. They occur especially as proteins, often conjugated. The term was first used by organic chemist Ludwig Brieger (1849–1919), derived ...

s that act as superantigens which directly activate the

T-cell T cells (also known as T lymphocytes) are an important part of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell receptor (TCR) on their ce ...

s over the variable domain of T-cell receptors. Nonetheless ''Staphylococcus aureus'' can by found in almost all patients affected by this disorder, while it is detected in only 20–30% of non-affected people. As ''Staphylococcus aureus'' is not always found in people with folliculitis decalvans, other factors must be present. Through examinations in families it was found that there is a family connection to the occurrences, which leads to the conclusion that there is a

genetic predisposition Genetic predisposition refers to a genetic characteristic which influences the possible phenotypic development of an individual organism within a species or population under the influence of environmental conditions. The term genetic susceptibil ...

for it; for example, patients with folliculitis decalvans could have a hereditary different opening of the hair follicle that could facilitate the lodging of the bacteria. Immunologically, another possibility is that especially strong intercellular fixation protein

ICAM-1 ICAM-1 (Intercellular adhesion molecule, Intercellular Adhesion Molecule 1) also known as CD54 (Cluster of Differentiation 54) is a protein that in humans is encoded by the ''ICAM1'' gene. This gene encodes a cell surface glycoprotein which is ty ...

contributes to inflammation with its strong effect of attracting white blood cells such as granulocytes and lymphocytes.

Diagnosis

Management

While there is no cure currently for Folliculitis Decalvans, there are treatments that have brought some patients ongoing relief from painful symptoms. One study available in the 'Journal of the American Academy of Dertmatology' indicates that of 23 patients, 21 of the study subjects with biopsy-proven FD found great relief with the Biologic Humira, citing picture and documented evidence. It is not yet known the full cause of the disease, but recent findings suggest an autoimmune component. In the vast majority of patients the bacteria Staphylococcus Aureus is present and has had minor success with a combination therapy of Clindamycin and Rifampin, although the rate of relief after this therapy is stopped is unknown. To date, Humira shows the best long-term therapeutic relief for patients with this painful disease that causes pustules, hair loss and excessive inflammation. Source: https://www.jaad.org/article/S0190-9622(22)00358-9/fulltext

Epidemiology

This disorder was first described by Charles-Eugène Quinquaud in 1888. He isolated

bacteria Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...

from the hair follicles of affected patients and introduced them in rats, mice and rabbits, with no result. In 1905 it was then differentiated from other scarring

alopecia Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scarring ...

s and the name Folliculitis decalvans, that remains current, was introduced. About 11% of the occurrences of scarring alopecias are of this type. Men are more commonly affected than women and its appearance is usually between the late teens and middle adult years. According to studies in the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

African Americans African Americans, also known as Black Americans and formerly also called Afro-Americans, are an American racial and ethnic group that consists of Americans who have total or partial ancestry from any of the Black racial groups of Africa ...

are more frequently affected than

White Americans White Americans (sometimes also called Caucasian Americans) are Americans who identify as white people. In a more official sense, the United States Census Bureau, which collects demographic data on Americans, defines "white" as " person hav ...

References

External links