Monilethrix | |
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Other names | Moniliform hair syndrome |
Beaded hair (60x magnification). | |
Specialty | Medical genetics |
Monilethrix (also referred to as beaded hair) [1] is a rare autosomal dominant hair disease that results in short, fragile, broken hair that appears beaded. [2] [3] It comes from the Latin word for necklace (monile) and the Greek word for hair (thrix). [4] Hair becomes brittle, and breaks off at the thinner parts between the beads. It appears as a thinning or baldness of hair and was first described in 1897 by Walter Smith [5]
Some indicators of monilethrix are small bumps on the skin, mainly on the scalp, neck and arms. In most cases, firm, dark papules, covered with dark scales and crusts appears on the skin, especially the scalp. [6] The affected individual would have beaded hair strands. The possible areas for the hair loss are the eyebrows, eyelashes, limbs, and pubic region. Hair strands are usually dull, dry, and brittle. The strands are prone to mild to severe breakage, causing onset alopecia, especially during pregnancy. Fingernail and toenails tend to appear abnormal. [7] The onset for this disease varies from person to person. The frequency of monilethrix is currently unknown.
Newborns are not born with Monilethrix; it usually develops within the first few months of life. The presentation may be of alopecia (baldness). Individuals vary in severity of symptoms. Nail deformities may also be present as well as hair follicle keratosis and follicular hyperkeratosis.[ citation needed ] Depending on severity it can effect hair on all areas of the body including head hair, arm and leg hair, pubic hair, underarm hair, eyebrows, and eyelashes. The hair is seen under a microscope with bumps in the hair strand. These cause the hair to be brittle and break in the thinner sections. Severe cases of monilethrix can also affect finger and toe nails causing abnormal growth. Monilethrix can also cause keratosis pilaris (small bumps on the skin). Less severe cases of Monilethrix may only affect certain parts of the scalp, usually the back of the head and neck.
Monilethrix may be diagnosed with trichoscopy [8] [9] and other forms of dermoscopy. Light microscopic examination is diagnostic and reveals elliptical nodes of normal thickness and intermittent constrictions, internodes at which the hair easily breaks. Under examination, the hair is beaded. The beading is the result of a periodic narrowing of the shaft with nodes separated by about 0.7 mm. [10] In general, there is a tendency for spontaneous improvement with time, especially during puberty and pregnancy, but the condition never disappears completely. [11]
Monilethrix is caused by mutations affecting the genes KRTHB1 (KRT81), KRTHB3 (KRT83), or KRTHB6 (KRT86) which code for type II hair cortex keratins. [12] The disorder is inherited in an autosomal dominant manner. [2] This means that the defective gene(s) responsible for the disorder is located on an autosome, and only one copy of the gene is sufficient to cause the disorder, when inherited from a parent who has the disorder.[ citation needed ] If an affected parent and an unaffected parent have children, 75% of the time they will be affected by Monilethrix. It can be equally present in both males and females.
No specific treatment exists for monilethrix. Spontaneous resolution following puberty has occurred in some cases. In affected females, the condition improves during pregnancy. Genetic counseling will be of benefit for affected individuals and their families. Other treatment is symptomatic and supportive. [6]
Currently, the frequency for this disease is unknown and affects both men and women. Signs and symptoms either show up spontaneously at birth or around the age of 2. [6] The symptoms may change or remain the same throughout one's life, but are usually present after the first few months after birth.
Alopecia areata, also known as spot baldness, is a condition in which hair is lost from some or all areas of the body. It often results in a few bald spots on the scalp, each about the size of a coin. Psychological stress and illness are possible factors in bringing on alopecia areata in individuals at risk, but in most cases there is no obvious trigger. People are generally otherwise healthy. In a few cases, all the hair on the scalp is lost, or all body hair is lost. Hair loss can be permanent, or temporary.
Cardiofaciocutaneous (CFC) syndrome is an extremely rare genetic disorder, and is one of the RASopathies. It was first described in 1986.
Lamellar ichthyosis, also known as ichthyosis lamellaris and nonbullous congenital ichthyosis, is a rare inherited skin disorder, affecting around 1 in 600,000 people.
Darier's disease (DAR) is a rare, inherited skin disorder that presents with multiple greasy, crusting, thick brown bumps that merge into patches. It is an autosomal dominant disorder discovered by French dermatologist Ferdinand-Jean Darier.
Telogen effluvium is a scalp disorder characterized by the thinning or shedding of hair resulting from the early entry of hair in the telogen phase. It is in this phase that telogen hairs begin to shed at an increased rate, where normally the approximate rate of hair loss is 125 hairs per day.
Keratosis pilaris is a common, autosomal-dominant, genetic condition of the skin's hair follicles characterized by the appearance of possibly itchy, small, gooseflesh-like bumps, with varying degrees of reddening or inflammation. It most often appears on the outer sides of the upper arms, thighs, face, back, and buttocks; KP can also occur on the hands, and tops of legs, sides, or any body part except glabrous (hairless) skin. Often the lesions can appear on the face, which may be mistaken for acne or folliculitis.
Tinea capitis is a cutaneous fungal infection (dermatophytosis) of the scalp. The disease is primarily caused by dermatophytes in the genera Trichophyton and Microsporum that invade the hair shaft. The clinical presentation is typically single or multiple patches of hair loss, sometimes with a 'black dot' pattern, that may be accompanied by inflammation, scaling, pustules, and itching. Uncommon in adults, tinea capitis is predominantly seen in pre-pubertal children, more often boys than girls.
Palmoplantar keratodermas are a heterogeneous group of disorders characterized by abnormal thickening of the stratum corneum of the palms and soles.
Meleda disease (MDM) or "mal de Meleda", also called Mljet disease, keratosis palmoplantaris and transgradiens of Siemens, is an extremely rare autosomal recessive congenital skin disorder in which dry, thick patches of skin develop on the soles of the hands and feet, a condition known as palmoplantar hyperkeratosis. Meleda Disease is a skin condition which usually can be identified not long after birth. This is a genetic condition but it is very rare. The hands and feet usually are the first to show signs of the disease but the disease can advance to other parts of the body. Signs of the disease include thickening of the skin, on hands and soles of feet, which can turn red in color. There currently is no cure and treatment is limited, but Acitretin can be used in severe cases.
Albinism-black lock-cell migration disorder is the initialism for the following terms and concepts that describe a condition affecting a person's physical appearance and physiology: (1) A – albinism, (2) B – black lock of hair, (3) C – cell migration disorder of the neurocytes of the gut, and (4) D – sensorineural deafness. The syndrome is caused by mutation in the endothelin B receptor gene (EDNRB).
Dermatoscopy also known as dermoscopy or epiluminescence microscopy, is the examination of skin lesions with a dermatoscope. It is a tool similar to a camera to allow for inspection of skin lesions unobstructed by skin surface reflections. The dermatoscope consists of a magnifier, a light source, a transparent plate and sometimes a liquid medium between the instrument and the skin. The dermatoscope is often handheld, although there are stationary cameras allowing the capture of whole body images in a single shot. When the images or video clips are digitally captured or processed, the instrument can be referred to as a digital epiluminescence dermatoscope. The image is then analyzed automatically and given a score indicating how dangerous it is. This technique is useful to dermatologists and skin cancer practitioners in distinguishing benign from malignant (cancerous) lesions, especially in the diagnosis of melanoma.
Papillon–Lefèvre syndrome (PLS), also known as palmoplantar keratoderma with periodontitis, is an autosomal recessive genetic disorder caused by a deficiency in cathepsin C.
Hypohidrotic ectodermal dysplasia is one of about 150 types of ectodermal dysplasia in humans. Before birth, these disorders result in the abnormal development of structures including the skin, hair, nails, teeth, and sweat glands.
Conradi–Hünermann syndrome is a rare type of chondrodysplasia punctata. It is associated with the EBP gene and affects between one in 100,000 and one in 200,000 babies.
Dermatopathia pigmentosa reticularis(DPR) is a rare, autosomal dominant congenital disorder that is a form of ectodermal dysplasia. Dermatopathia pigmentosa reticularis is composed of the triad of generalized reticulate hyperpigmentation, noncicatricial alopecia, and onychodystrophy. DPR is a non life-threatening disease that largely affects the skin, hair, and nails. It has also been identified as a keratin disorder. Historically, as of 1992, only 10 cases had been described in world literature; however, due to recent advances in genetic analysis, five additional families studied in 2006 have been added to the short list of confirmed cases.
Erythrokeratodermia variabilis is a rare autosomal dominant disorder that usually presents at birth or during the first year of life. To date, it is thought to be caused by mutations in genes encoding for connexin channels proteins in the epidermis, leading to the misregulation of homeostasis in keratinocytes.
Trichoscopy is a method of hair and scalp evaluation and is used for diagnosing hair and scalp diseases. The method is based on dermoscopy. In trichoscopy hair and scalp structures may be visualized at many-fold magnification. Currently magnifications ranging from 10-fold to 70-fold are most popular in research and clinical practice.
Trichothiodystrophy (TTD) is an autosomal recessive inherited disorder characterised by brittle hair and intellectual impairment. The word breaks down into tricho – "hair", thio – "sulphur", and dystrophy – "wasting away" or literally "bad nourishment". TTD is associated with a range of symptoms connected with organs of the ectoderm and neuroectoderm. TTD may be subclassified into four syndromes: Approximately half of all patients with trichothiodystrophy have photosensitivity, which divides the classification into syndromes with or without photosensitivity; BIDS and PBIDS, and IBIDS and PIBIDS. Modern covering usage is TTD-P (photosensitive), and TTD.
Clouston's hidrotic ectodermal dysplasia is a medical condition caused by mutations in a connexin gene, GJB6 or connexin-30, characterized by scalp hair that is wiry, brittle, and pale. It is often associated with patchy alopecia.
Lidia Rudnicka is a Polish-American dermatologist with contributions to the field of scleroderma research, hair diseases and melanoma prevention.