Conditions of the skin appendages

Leukonychia (or leuconychia), also known as white nails or milk spots, is a medical term for white discoloration appearing on nails.

Menkes disease (MNK), also known as Menkes syndrome, is an X-linked recessive disorder that affects copper levels in the body, leading to copper deficiency.

A whitlow or felon is an infection of the tip of the finger.

Onychomycosis is a fungal infection of the nail.

Hirsutism is excessive body hair in women on parts of the body where hair is normally absent or minimal, such as on the chin or chest.

Nail biting, also known as onychophagy or onychophagia, is an oral compulsive habit.

Nail diseases are distinct from diseases of the skin.

Onychocryptosis (from Greek ὄνυξ onyx "nail" + κρυπτός kryptos "hidden"), also known as an ingrown toenail, or unguis incarnates, is a common form of nail disease.

Hidradenitis is any disease in which the histologic abnormality is primarily an inflammatory infiltrate around the eccrine glands.

Hyperhidrosis is a condition characterized by abnormally increased sweating, in excess of that required for regulation of body temperature.

Folliculitis is the infection and inflammation of one or more hair follicles.

A paronychia (/ˌpærəˈnɪkiə/; Greek: παρωνυχία from para, "around" and onukh-, "nail") is a nail disease that is an often-tender bacterial or fungal infection of the hand or foot where the nail and skin meet at the side or the base of a finger or toenail.

Onycholysis refers to the detachment of the nail from the nail bed, usually starting at the tip and/or sides.

Rubinstein–Taybi syndrome (RTS), also known as broad thumb-hallux syndrome or Rubinstein syndrome, is a condition characterized by short stature, moderate to severe learning difficulties, distinctive facial features, and broad thumbs and first toes.

Hypertrichosis (also called Ambras syndrome) is an abnormal amount of hair growth over the body; extensive cases of hypertrichosis have informally been called werewolf syndrome, because the appearance is similar to the mythical werewolf.

Trichotillomania, also known as hair pulling disorder, is an impulse control disorder characterised by a long term urge that results in the pulling out of one's hair.

Pityriasis amiantacea (also known as "Tinea amiantacea") is an eczematous condition of the scalp resulting in hair loss in which thick tenaciously adherent scale infiltrates and surrounds the base of a group of scalp hairs.

In racquet nails (also known as brachyonychia, nail en raquette, and racquet thumb), the nail plate is flattened, the end of the thumb is widened and flattened, and the distal phalanx is abnormally short.

Reactive perforating collagenosis is a rare, familial, nonpuritic skin disorder characterized by papules that grow in a diameter of 4 to 6mm and develop a central area of umbilication to which keratinous material is lodged.

Acquired idiopathic generalized anhidrosis (AIGA) is characterized by generalized absence of sweating without other autonomic and neurologic dysfunction.

Pseudofolliculitis barbae (/ˈsjuːdoʊfəˈlɪkjʊˈlaɪtᵻs ˈbɑːrbiː/; PFB), also known as barber's itch, folliculitis barbae traumatica, razor bumps, scarring pseudofolliculitis of the beard, and shave bumps, is a medical term for persistent irritation caused by shaving.

An epidermoid cyst is a benign cyst usually found on the skin.

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 (the resting phase of the hair follicle).

Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body.

A subungual hematoma is a collection of blood (hematoma) underneath a toenail or fingernail (black toenail).

Paraneoplastic acrokeratosis, Bazex syndrome (also known as acrokeratosis paraneoplastica of Bazex and acrokeratosis neoplastica) is a cutaneous condition characterized by psoriasiform changes of hands, feet, ears, and nose, with involvement of the nails and periungual tissues being characteristic and indistinguishable from psoriatic nails.

Alopecia mucinosa (also known as "Follicular mucinosis," "Mucinosis follicularis,", "Pinkus’ follicular mucinosis," and "Pinkus’ follicular mucinosis–benign primary form") is a skin disorder that generally presents, but not exclusively, as erythematous plaques or flat patches without hair primarily on the scalp and face.

Alopecia universalis (AU) or alopecia areata universalis is a medical condition involving loss of all hair, including eyebrows and eyelashes.

Alopecia totalis is the loss of all skull and facial hair.

Atrichia with papular lesions (aka "Papular atrichia") is a diffuse hair loss caused by an abnormality of the human homologue of the mouse hairless gene.

Mees' lines or Aldrich–Mees' lines, also called leukonychia striata, are lines of discoloration across the nails of the fingers and toes.

Fox–Fordyce disease, or apocrine miliaria, is a chronic blockage of the sweat gland ducts with a secondary, non-bacterial inflammatory response to the secretions and cellular debris in the cysts.

Blue nails, or more formally azure lunula, are characterized by a blue discoloration of the lunulae, seen in argyria and cases of hepatolenticular degeneration (Wilson's disease), also having been reported in hemoglobin M disease and hereditary acrolabial telangiectases.

Uncombable hair syndrome, also known as Pili trianguli et canaliculi, Spun-glass hair, and Cheveux incoiffables, is a rare structural anomaly of the hair with a variable degree of effect.

Generalized hyperhidrosis is excessive sweating that may be induced by febrile diseases, vigorous exercise, or a hot, humid environment, such as a tropical milieu.

Green nail syndrome, also known as chloronychia, is a paronychial infection caused due to Pseudomonas aeruginosa that can develop in individuals whose hands are frequently submerged in water.

Kyrle disease or hyperkeratosis follicularis et parafollicularis in cutem penetrans is identified as a form of an acquired perforating disease.

Woolly hair nevus (alternatively spelled "Wooly hair nevus") is a congenital condition in which hair in a circumscribed area of the scalp is kinked or woolly.

Marie Unna hereditary hypotrichosis (also known as "Marie Unna hypotrichosis") is an autosomal dominant condition characterized by scalp hair that is sparse or absent at birth, with variable coarse, wiry hair regrowth in childhood, and potential loss again at puberty.

Ophiasis is a form of alopecia areata characterized by the loss of hair in the shape of a wave at the circumference of the head.

Onychotillomania is a compulsive neurosis in which a person picks constantly at the nails or tries to tear them off.

Yellow nail syndrome, also known as "primary lymphedema associated with yellow nails and pleural effusion," is a very rare medical syndrome that includes pleural effusions, lymphedema (due to under development of the lymphatic vessels) and yellow dystrophic nails.

A milium (plural milia), also called a milk spot or an oil seed, is a clog of the eccrine duct, the true sweat gland.

Nail–patella syndrome (NPS) (also known as "HOOD syndrome") is a genetic disorder that results in small, poorly developed nails and kneecaps, but can also affect many other areas of the body, such as the elbows, chest, and hips.

Onychogryphosis (also known as onychogryposis or ram's horn nails) is a hypertrophy that may produce nails resembling claws or a ram's horn.

Ross' syndrome consists of Adie's syndrome (myotonic pupils and absent deep tendon reflexes) plus segmental anhidrosis (typically associated with compensatory hyperhidrosis).

Trichomycosis axillaris is a superficial bacterial colonization of the hair shafts in sweat gland–bearing areas, such as the armpits and the groin.

Anagen effluvium is the pathologic loss of anagen or growth-phase hairs.

Anonychia is the absence of nails, an anomaly, which may be the result of a congenital ectodermal defect, ichthyosis, severe infection, severe allergic contact dermatitis, self-inflicted trauma, Raynaud phenomenon, lichen planus, epidermolysis bullosa, or severe exfoliative diseases.

Cutaneous perforating disorders include the following: * Acquired perforating dermatosis (Acquired perforating collagenosis) * Kyrle disease * Perforating folliculitis

Onychauxis presents with thickened nails without deformity, and this simple thickening may be the result of trauma, acromegaly, Darier's disease, psoriasis, or pityriasis rubra pilaris, or, in some cases, hereditary.

Onychorrhexis, (from the words in Greek: onycho-, nail, rhexis-, bursting) also known as Brittle nails, is a brittleness with breakage of finger or toenails that may result from excessive strong soap and water exposure, nail polish remover, hypothyroidism, anemia, anorexia nervosa or bulimia, or after oral retinoid therapy.

Psoriatic nails is a nail disease.

Trachyonychia, sometimes called sandpapered nails, is a condition characterized by rough accentuated linear ridges (longitudinal striations) on the nails of the fingers and toes.

Pili annulati (also known as "Ringed hair") is a genetic trait in which the hair seems banded by alternating segments of light and dark color when seen in reflected light.

Pili torti (also known as "Twisted hairs") is characterized by short and brittle hairs that appear flattened and twisted when viewed through a microscope.

Pili bifurcati is characterized by bifurcation found in short segments along the shafts of several hairs, with each branch of the bifurcation being covered with its own cuticle.

Pattern hair loss, known as male-pattern hair loss (MPHL) when it affects males and female-pattern hair loss (FPHL) when it affects females, is hair loss that primarily affects the top and front of the scalp.

Beau's lines are deep grooved lines that run from side to side on the fingernail or the toenail.

Darier's disease (DAR), also known as Darier disease, Darier–White disease, Dyskeratosis follicularis and Keratosis follicularis, is an autosomal dominant disorder discovered by French dermatologist Ferdinand-Jean Darier.

Neutrophilic eccrine hidradenitis (NEH) usually is a cutaneous complication of chemotherapy, but it can also occur for other reasons.

Ingrown hair is a condition where hair curls back or grows sideways into the skin.

Koilonychia (from the Greek: koilos-, hollow, onikh-, nail), also known as spoon nails, is a nail disease that can be a sign of hypochromic anemia, especially iron-deficiency anemia.

Monilethrix (also referred to as beaded hair) is a rare autosomal dominant hair disease that results in short, fragile, broken hair that appears beaded.

Chromhidrosis (also referred to as "colored sweat") is a rare condition characterized by the secretion of colored sweat.

Granulosis rubra nasi is a rare familial disease of children, occurring on the nose, cheeks, and chin, characterized by diffuse redness, persistent hyperhidrosis, and small dark red papules that disappear on diascopic pressure.

Pachyonychia congenita is an autosomal dominant skin disorder.

Alopecia areata, also known as spot baldness, is an autoimmune disease in which hair is lost from some or all areas of the body, usually from the scalp due to the body's failure to recognize its own body cells and subsequent destruction of its own tissue.

Scarring hair loss, also known as cicatricial alopecia, is the loss of hair which is accompanied with scarring.

Congenital hypertrophy of the lateral fold of the hallux is a rare cutaneous condition of unknown pathology that present to newborns.

Sabinas brittle hair syndrome, also called Sabinas syndrome or brittle hair-mental deficit syndrome, is an autosomal recessive congenital disorder affecting the integumentary system.

Traction alopecia is a form of alopecia, or gradual hair loss, caused primarily by pulling force being applied to the hair.

Trichorrhexis invaginata (also known as "Bamboo hair" ) is a distinctive hair shaft abnormality that may occur sporadically, either in normal hair or with other hair shaft abnormalities, or regularly as a marker for Netherton's syndrome.

Trichorrhexis nodosa is a defect in the hair shaft characterized by thickening or weak points (nodes) that cause the hair to break off easily.

Trichostasis spinulosa is a common but rarely diagnosed disorder of the hair follicles that clinically gives the impression of blackheads, but the follicles are filled with funnel-shaped, horny plugs which are bundles of vellus hairs.