Acne, also known as acne vulgaris, is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and possible scarring. It primarily affects skin with a relatively high number of oil glands, including the face, upper part of the chest, and back. The resulting appearance can lead to lack of confidence, anxiety, reduced self-esteem, and, in extreme cases, depression or thoughts of suicide.
Folliculitis is the infection and inflammation of one or more hair follicles. The condition may occur anywhere on hair-covered skin. The rash may appear as pimples that come to white tips on the face, chest, back, arms, legs, buttocks, or head.
A sebaceous gland or oil gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest number on the face and scalp, but also on all parts of the skin except the palms of the hands and soles of the feet. In the eyelids, meibomian glands, also called tarsal glands, are a type of sebaceous gland that secrete a special type of sebum into tears. Surrounding the female nipple, areolar glands are specialized sebaceous glands for lubricating the nipple. Fordyce spots are benign, visible, sebaceous glands found usually on the lips, gums and inner cheeks, and genitals.
Hidradenitis suppurativa (HS), sometimes known as acne inversa or Verneuil's disease, is a long-term dermatological condition characterized by the occurrence of inflamed and swollen lumps. These are typically painful and break open, releasing fluid or pus. The areas most commonly affected are the underarms, under the breasts, perineum, buttocks, and the groin. Scar tissue remains after healing. HS may significantly limit many everyday activities, for instance, walking, hugging, moving, and sitting down. Sitting disability may occur in patients with lesions in sacral, gluteal, perineal, femoral, groin or genital regions; and prolonged periods of sitting down can also worsen the condition of the skin of these patients.
Cutibacterium acnes is the relatively slow-growing, typically aerotolerant anaerobic, gram-positive bacterium (rod) linked to the skin condition of acne; it can also cause chronic blepharitis and endophthalmitis, the latter particularly following intraocular surgery. Its genome has been sequenced and a study has shown several genes can generate enzymes for degrading skin and proteins that may be immunogenic.
Demodicosis, also called Demodex folliculitis in humans and demodectic mange or red mange in animals, is caused by a sensitivity to and overpopulation of Demodex spp. as the host's immune system is unable to keep the mites under control.
Propionibacterium is a gram-positive, anaerobic, rod-shaped genus of bacteria named for their unique metabolism: They are able to synthesize propionic acid by using unusual transcarboxylase enzymes.
A boil, also called a furuncle, is a deep folliculitis, which is an infection of the hair follicle. It is most commonly caused by infection by the bacterium Staphylococcus aureus, resulting in a painful swollen area on the skin caused by an accumulation of pus and dead tissue. Boils are therefore basically pus-filled nodules. Individual boils clustered together are called carbuncles. Most human infections are caused by coagulase-positive S. aureus strains, notable for the bacteria's ability to produce coagulase, an enzyme that can clot blood. Almost any organ system can be infected by S. aureus.
Cradle cap causes crusty or oily scaly patches on a baby's scalp. The condition is not painful or itchy, but it can cause thick white or yellow scales that are not easy to remove. Cradle cap most commonly begins sometime in the first three months but can occur in later years. Similar symptoms in older children are more likely to be dandruff than cradle cap. The rash is often prominent around the ear, the eyebrows or the eyelids. It may appear in other locations as well, where it is called infantile seborrhoeic dermatitis. Cradle cap is just a special—and more benign—case of this condition. The exact cause of cradle cap is not known. Cradle cap is not spread from person to person (contagious). It is also not caused by poor hygiene. It is not an allergy, and it is not dangerous. Cradle cap often lasts a few months. In some children, the condition can last until age 2 or 3.
A comedo is a clogged hair follicle (pore) in the skin. Keratin combines with oil to block the follicle. A comedo can be open (blackhead) or closed by skin (whitehead) and occur with or without acne. The word "comedo" comes from the Latin comedere, meaning "to eat up", and was historically used to describe parasitic worms; in modern medical terminology, it is used to suggest the worm-like appearance of the expressed material.
Acne is acneiform eruptions. It is usually used as a synonym for acne vulgaris, but may also refer to:
Acneiform eruptions, or acne mimicking eruptions, are a group of skin conditions characterized by small bumps resembling acne. Typically, these bumps are mostly of similar size. Some bumps may be bigger or contain fluid. Generally, blackheads and whiteheads are absent. It tends to appear suddenly, with the chest and back most frequently affected.
Neonatal acne, also known as acne neonatorum, is a type of acne that develops in newborns, typically before 6 weeks of life. It presents with open and closed comedones on the cheeks, chin and forehead.
Acne mechanica is an acneiform eruption that has been observed after repetitive physical trauma to the skin such as rubbing, occurring from clothing or sports equipment. In addition to those mechanisms, the skin not getting enough exposure to air also contributes to the formation of acne mechanica. It is often mistaken as a rash that forms on sweaty skin that is constantly being rubbed, but in reality, it is a breakout of acne mechanica. The term "acne" itself describes the occurrence in which hair follicles in the skin get clogged by oil, dead skin cells, dirt and bacteria, or cosmetic products and create a pimple. Pimples can vary in type, size, and shape, but the sole basis of them occurring is the same - the oil gland in the pore becomes clogged and sometimes infected, which creates pus in order to fight the infection and subsequently causes the development of swollen, red lesions on the skin.
Gnathophyma involves swelling of the chin. It is a type of lesion associated with rosacea, a common chronic inflammatory skin disorder of the sebaceous glands characterized by redness, swelling, and acne-like pustules.
A pimple or zit is a kind of comedo that results from excess sebum and dead skin cells getting trapped in the pores of the skin. In its aggravated state, it may evolve into a pustule or papule. Pimples can be treated by acne medications, antibiotics, and anti-inflammatories prescribed by a physician, or various over the counter remedies purchased at a pharmacy.
Infantile acne is a form of acne that begins in very young children. Typical symptoms include inflammatory and noninflammatory lesions, papules and pustules most commonly present on the face. No cause of infantile acne has been established but it may be caused by increased sebaceous gland secretions due to elevated androgens, genetics and the fetal adrenal gland causing increased sebum production. Infantile acne can resolve by itself by age 1 or 2. However, treatment options include topical benzyl peroxide, topical retinoids and topical antibiotics in most cases.
Sebaceous adenitis in an uncommon skin disease found in some breeds of dog, and more rarely in cats, rabbits and horses. characterised by an inflammatory response against the dog's sebaceous glands, which can lead to the destruction of the gland. It was first described in veterinary literature in the 1980s.
Fiddler's neck is an occupational disease that affects violin and viola players.
Familial disseminated comedones without dyskeratosis (FDCWD) is a rare autosomal dominant skin disorder characterized by the presence of numerous comedones on the face, trunk, and extremities. The comedones are typically asymptomatic and do not lead to scarring. The disorder is thought to be caused by a mutation in the gene encoding the protein involucrin.
