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, hair, nails, and related muscle and glands. The major function of this system is as a barrier against the external environment.
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.
Hyperpigmentation is the darkening of an area of skin or nails caused by increased melanin.
Cutis laxa or pachydermatocele is a group of rare connective tissue disorders in which the skin becomes inelastic and hangs loosely in folds.
Epidermolysis bullosa simplex (EBS), is a disorder resulting from mutations in the genes encoding keratin 5 or keratin 14.
Flat warts, technically known as Verruca plana, are reddish-brown or flesh-colored, slightly raised, flat-surfaced, well-demarcated papule of 2 to 5 mm in diameter. Upon close inspection, these lesions have a surface that is "finely verrucous". Most often, these lesions affect the hands, legs, or face, and a linear arrangement is not uncommon. At histopathology, flat warts have cells with prominent perinuclear vacuolization around pyknotic, basophilic, centrally located nuclei that may be located in the granular layer. These are referred to as "owl's eye cells."
Muehrcke's nails or Muehrcke's lines are changes in the fingernail that may be a sign of an underlying medical condition. The term refers to a set of one or more pale transverse bands extending all the way across the nail, parallel to the lunula. In contrast to Beau's lines, they are not grooved, and in contrast to Mees' lines, the thumb is usually not involved.
Pili torti is characterized by short and brittle hairs that appear flattened and twisted when viewed through a microscope.
Loose anagen syndrome is primarily described in fair-haired children who have easily dislodgable hair.
Prurigo gestationis is an eruption consisting of pruritic, excoriated papules of the proximal limbs and upper trunk, most often occurring between the 20th and 34th week of gestation.
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.
Erosive pustular dermatitis of the scalp presents with pustules, erosions, and crusts on the scalp of primarily older Caucasian females, and on biopsy, has a lymphoplasmacytic infiltrate with or without foreign body giant cells and pilosebaceous atrophy.
Pili annulati is a genetic trait in which the hair seems banded by alternating segments of light and dark color when seen in reflected light.
Alopecia mucinosa is a skin disorder that generally presents, but not exclusively, as erythematous plaques or flat patches without hair primarily on the scalp, neck and face. This can also be present on the body as a follicular mucinosis and may represent a systemic disease.
Small plaque parapsoriasis characteristically occurs with skin lesions that are round, oval, discrete patches or thin plaques, mainly on the trunk.
Reticular pigmented anomaly of the flexures is a fibrous anomaly of the flexures or bending parts of the axillae, neck and inframammary/sternal areas. It is an autosomal-dominant pigmentary disorder that may appear in adolescence or adulthood. This condition is due to mutations in structural/desmosomal proteins found within stratified squamous epithelium.
Keratoderma climactericum is a skin condition characterized by hyperkeratosis of the palms and soles beginning at about the time of menopause.
Lichen striatus is a rare skin condition that is seen primarily in children, most frequently appearing ages 5–15. It consists of a self-limiting eruption of small, scaly papules.
Cutaneous actinomycosis is a chronic disease that affects the deep subcutaneous tissue of the skin. Caused by an anaerobic, Gram-positive, filamentous type of bacteria in the genus Actinomyces, invasion of the soft tissue leads to the formation of abnormal channels leading to the skin surface that discharge pale yellow sulfur granules.
Topterone, also known as 17α-propyltestosterone or as 17α-propylandrost-4-en-17β-ol-3-one, is a steroidal antiandrogen that was first reported in 1978 and was developed for topical administration but, due to poor effectiveness, was never marketed.
