A sebaceous 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.
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 system is as a barrier against the external environment.
Nevus is a nonspecific medical term for a visible, circumscribed, chronic lesion of the skin or mucosa. The term originates from nævus, which is Latin for "birthmark"; however, a nevus can be either congenital or acquired. Common terms, including mole, birthmark, and beauty mark, are used to describe nevi, but these terms do not distinguish specific types of nevi from one another.
Miliaria, commonly known as heat rash, sweat rash, or prickly heat, is a skin disease marked by small, itchy rashes due to sweat trapped under the skin by clogged sweat-gland ducts. Miliaria is a common ailment in hot and humid conditions, such as in the tropics and during the summer. Although it affects people of all ages, it is especially common in children and infants due to their underdeveloped sweat glands.
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.
Pearly penile papules are benign small bumps on the human penis. They vary in size from 1–4 mm, are pearly or flesh-colored, smooth and dome-topped or filiform, and appear in one or several rows around the corona, the ridge of the head of the penis and sometimes on the penile shaft. They are painless, non-cancerous and not harmful. The medical condition of having such papules is called hirsutoid papillomatosis or hirsuties papillaris coronae glandis.
Fordyce spots are harmless and painless visible sebaceous glands typically appearing as white/yellow small bumps or spots on the inside of lips or cheeks, gums, or genitalia. They are common, and are present in around 80% of adults. Treatment is generally not required and attempts to remove them typically result in pain and scarring.
Syringomas are benign eccrine sweat duct tumors, typically found clustered on eyelids, although they may also be found in the armpits, abdomen, chest, neck, scalp, or groin area, including genitals, in a symmetric pattern. They are skin-colored or yellowish firm, rounded bumps, 1–3 mm in diameter, and may be confused with xanthoma, milia, hidrocystoma, trichoepithelioma, and xanthelasma. They are more common in women and are most commonly found in middle-aged Asian women. While they can present at any time in life, they typically present during adolescence. They are usually not associated with any other symptoms, although can sometimes cause itchiness or irritation.
Pruritic urticarial papules and plaques of pregnancy (PUPPP), known in United Kingdom as polymorphic eruption of pregnancy (PEP), is a chronic hives-like rash that strikes some women during pregnancy. Some skin changes are known to occur in people who are pregnant while other skin conditions, or dermatoses, that people have prior to getting pregnant will become altered or symptoms will increase. Pruritic urticarial papules and plaques of pregnancy (PUPPP) is one of many skin conditions that is specific to pregnancy and occurs in about 1 in every 160 (0.625%) of pregnancies.
Rhinophyma is a condition causing development of a large, bulbous nose associated with granulomatous infiltration, commonly due to untreated rosacea. The condition is most common in older white males.
Stomatitis nicotina is a diffuse white patch on the hard palate, usually caused by tobacco smoking, usually pipe or cigar smoking. It is painless, and it is caused by a response of the palatal oral mucosa to chronic heat. A more pronounced appearance can occur with reverse smoking, sometimes distinguished from stomatitis nicotina by the term reverse smoker's stomatitis. While stomatitis nicotina that is caused by heat is not a premalignant condition, the condition that is caused by reverse smoking is premalignant.
Grover's disease (GD) is a polymorphic, pruritic, papulovesicular dermatosis characterized histologically by acantholysis with or without dyskeratosis. Once confirmed, most cases of Grover's disease last six to twelve months, which is why it was originally called "transient". However it may last much longer. Nevertheless, it is not to be confused with relapsing linear acantholytic dermatosis.
A blue nevus is a type of coloured mole, typically a single well-defined blue-black bump.
Neonatal acne, also known as acne neonatorum, is an acneiform eruption that occurs in newborns or infants within the first 4-6 weeks of life, and presents with open and closed comedones on the cheeks, chin and forehead.
Eccrine angiomatous hamartoma (EAH), first described by Lotzbeck in 1859, is a rare benign vascular hamartoma characterized histologically by a proliferation of eccrine and vascular components. EAH exists on a spectrum of cutaneous tumors that include eccrine nevus, mucinous eccrine nevus and EAH. Each diagnostic subtype is characterized by an increase in the number as well as size of mature eccrine glands or ducts, with EAH being distinguished by the added vascular component.
Sebaceous carcinoma, also known as sebaceous gland carcinoma (SGc), sebaceous cell carcinoma, and meibomian gland carcinoma is an uncommon malignant cutaneous tumor. Most are typically about 1.4 cm at presentation. SGc originates from sebaceous glands in the skin and, therefore, may originate anywhere in the body where these glands are found. SGc can be divided into 2 types: periocular and extraocular. The periocular region is rich in sebaceous glands making it a common site of origin. The cause of these lesions in the vast majority of cases is unknown. Occasional cases may be associated with Muir-Torre syndrome. SGc accounts for approximately 0.7% of all skin cancers, and the incidence of SGc is highest in Caucasian, Asian, and Indian populations. Due to the rarity of this tumor and variability in clinical and histological presentation, SGc is often misdiagnosed as an inflammatory condition or a more common neoplasm. SGc is commonly treated with wide local excision or Mohs micrographic surgery, and the relative survival rates at 5 and 10 years are 92.72 and 86.98%, respectively.
Heck's disease, also known as Focal Epithelial Hyperplasia, is an asymptomatic, benign neoplastic condition characterized by multiple white to pinkish papules that occur diffusely in the oral cavity. Can present with slightly pale, smooth or roughened surface morphology. It is caused by the human papilloma virus types 13 and 32. It exhibits surface cells with vacuolated cytoplasm around irregular, pyknotic nuclei and occasional cells with mitosis-like changes within otherwise mature and well-differentiated epithelium. A distinguishing histologic feature is elongated rete ridges with mitosoid bodies. It shows 'cobblestone' appearance clinically. It was first identified in the Aboriginal population of North America.
A sebaceous adenoma, a type of adenoma, a cutaneous condition characterized by a slow-growing tumor usually presenting as a pink, flesh-coloured, or yellow papule or nodule.
Infantile acne is a form of acneiform eruption that occurs in infants from 6 weeks to 1 year of age. 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.
Photography of sebaceous hyperplasia, showing a group of papules, in this case on the chest with linear distribution pattern.
Dermoscopy of sebaceous hyperplasia. Note the aggregation of yellowish-white clods with linear vessels between or above the clods.
Dermoscopy of sebaceous hyperplasia with digital high dynamic range. Note the multi-lobulated clods with central openings.
H&E staining of biopsied lesion of sebaceous hyperplasia: Note the multiple, mature sebaceous lobules attached to the central dilated duct in the upper dermis.
Sebaceous hyperplasia, lateral right temple marked for biopsy with adjacent malignant melanoma in situ, evolving, medial right temple
Sebaceous hyperplasia with surrounding chronic folliculitis, right mid chest
