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Dermatology Library

T

Tanning:

UV radiation from the sun, tanning beds, or sun lamps may cause skin cancer. While skin cancer has been associated with sunburn, moderate tanning may also produce the same effect. UV radiation can also have a damaging effect on the immune system and cause premature aging of the skin, giving it a wrinkled, leathery appearance.

Also see: Sun Protection

Telangiectasia:

Telangiectasias are small dilated blood vessels near the surface of the skin or mucous membranes, usually measuring only a few millimeters. They can develop anywhere on the body but are commonly seen on the face around the nose, cheeks, and chin. They can also develop on the legs, specifically on the upper thigh, below the knee joint, and around the ankles. When seen on the legs they are often call spider veins. They can disappear temporarily if you press on them with your finger.

Telangiectasis are very common in healthy people and are usually caused by sun damage or aging. When seen on the legs, they do not necessarily indicate a vein disorder, such as varicose veins or underlying deep vein problems. However, they are seen with a number of disorders such as acne rosacea, birthmarks, scleroderma, several types of inherited disorders, or with prolonged use of oral or topical corticosteroids.

Typically no treatment is necessary unless the appearance is bothersome. Sclerotherapy and laser treatments are used to treat the areas if needed.

Submitted by: Nitra H. Cole, MSN, ARNP, NP-C

Thickness:

The thickness of a melanoma (how deeply the tumor extends into the skin) has been related to 5-year survival after surgical removal of the tumor. A physician named Alexander Breslow made this observation in 1975, and the relationship between tumor thickness and 5-year survival has been documented to be valid in years since:

Breslow Thickness (millimeters) 5-Year Survival (%)
less than 0.76 97
0.76-1.50 92
1.51-2.50 76
2.51-4.0 62
4.1-8.0 52
more than 8.0 32

Survival rates, like insurance survival tables, are statistical aggregates. Please keep in mind, it is impossible to determine survival for an individual patient.

Als see: Melanoma, Skin Cancer

Tinea:

Tinea (dermatophytosis) is a superficial fungal infection of the skin caused by dermatophytes. Although often called ringworm, tinea infections are not caused by worms. The infection may be spread from person to person, animal to person, or from soil to person. Tinea may cause itching and irritation to the skin or may be symptom free. Physical examination of the affected skin, evaluation of skin scrapings under the microscope, or culture tests are used to make a diagnosis of tinea. Tinea infections are classified according to the part of the body affected:

  • Tinea capitis is infection of scalp hair.
  • Tinea corporis is infection of the trunk and extremities.
  • Tinea manuum is infection of the palms and interdigital webs.
  • Tinea pedis is infection of the foot soles and interdigital webs.
  • Tinea cruris is infection of the groin.
  • Tinea barbae is infection of the beard area and neck.
  • Tinea faciale is infection of the face.
  • Tinea unguium is infection of the nail.

Tinea capitis Tinea capitis is an infection of the scalp. It most often occurs in children, but can be seen at any age. It appears as patchy, fine, white scales on the scalp and may be accompanied by hair thinning or hair loss. There may be inflammation to the scalp and in severe cases the patient may develop inflamed, boggy, tender nodules with purulent drainage. This is known as kerion.

Tinea corporis Tinea corporis infection typically occurs on the exposed skin of the trunk and extremities. It appears as annular, scaly plaques with raised edges, pustules, and vesicles. Central clearing on the plaques gives it an annular look prompting the term “ringworm.”

Tinea manuum is infection of the palms and finger webs. It usually occurs in association with tinea pedis, with both feet and one hand being involved. It appears as scaling and erythema to the hands and may develop into cracks and fissures.

Tinea pedia Tinea pedis (athlete’s foot) is a fungal infection of the feet and toe webs. It appears as mild redness and gray scaling of the feet. Predisposing factors for tinea pedis is wearing shoes that promote warmth and sweating, locker room floors, and community bath areas.

Tinea cruris (jock itch) affects the groin and pubic region. It may spread to the buttocks and thighs, but rarely to the scrotum. It appears as erythematous lesions with central clearing and raised borders. It is often very itchy and made worse by tight clothes and sweating.

Tinea barbae involves the beard, moustache, and neck area. It usually involves erythema, scaling, circular patches and inflammation with pustules or papules on the hair follicles. This infection is seen most commonly in those that work with farm animals.

Tinea facialis affects the face. Annular plaques with scaling and erythema develop on the face. The lesions are often very itchy.

Tinea unguium Tinea unguium (onychomycosis) is an infection of the nail plate. It affects both fingernails and toenails. The nails turn yellow, brown, or white and can become thick.

Tinea infections may be treated with topical or oral antifungal medications. Topical therapy for 2 weeks is generally effective in eliminating the fungus. Tinea unguium often requires at least 8-12 weeks of oral therapy. Oral therapy is also used for more extensive cases of fungal infections or those that do not respond to topical treatment.

Submitted by: Nitra H. Cole, MSN, ARNP, NP-C

Tinea Capitis and Tinea Barbae:

Tinea capitis is a mycotic infection by dermatophyte fungi involving scalp hair follicles and adjacent skin. Tinea capitis is caused by select species in the genera Microsporum and Trichophyton. A variety of inflammatory and non-inflammatory lesions, often with associated alopecia, may be present. There are three recognized patterns: ectothrix, endothrix, and favus. In ectothrix tinea capitis, hyphae fragment into arthroconidia (spores) outside the hair shaft. This eventually ends in cuticle destruction. There are inflammatory and non-inflammatory varieties of ectothrix tinea capitis. The non-inflammatory variety is often referred to as "gray patch," and the inflammatory variety, which may resemble bacterial furunculosis, is referred to as kerion. In endothrix tinea capitis, arthroconidia (spores) occur within the hair shaft and cuticle destruction does not occur. There are also non- inflammatory and inflammatory varieties of endothrix tinea capitis. The non- inflammatory type is often referred to as "black dot" because of hairs breaking close to the scalp, leaving a "black dot" appearance on scalp skin.

Favus rarely occurs in the United States but is more common in other countries, particularly Eastern Europe and parts of Asia. This type is characterized by arthroconidia (spores), air spaces, and fragmented hyphae within the hair shaft. Tinea barbae is similar to tinea capitis, but affects the hairs and follicles of beard and mustache areas. It is often caused by zoophilic dermatophytes.It is more common in rural areas. Tinea capitis may be misdiagnosed as alopecia areata, trichotillomania, bacterial furunculosis, seborrheic dermatitis, psoriasis, telogen effluvium, and atopic or seborrheic dermatitis. In untreated cases, severe scarring with permanent hair loss may result. This has psychosocial ramifications and may affect the social adjustment and self-image of the child. Early diagnosis and appropriate therapy are therefore critical in preventing scarring.

In general, systemic antifungal therapy is necessary in both tinea capitis and tinea barbae. Once treated, recurrences are uncommon. However, an asymptomatic carrier state may occur in some patients. This may contribute to the increased prevalence of some infections. Therefore in some instances, it is justified to treat asymptomatic adults and adolescent children who are exposed to the infected child.

Also see: Fungal Infections, Hair Loss

Tinea corporis:

Fungus affecting the skin of the trunk and extremities, characterized by both inflammatory and non-inflammatory lesions.

Also see: Fungal Infections

Tinea cruris:

Fungus infections affecting the proximal medial thighs and buttocks, characterized by inflammatory and non-inflammatory lesions often with invasion of hair follicles; cutaneous candidiasis in this region can mimic dermatophytic infection, but is usually associated with scrotal lesions.

Also see: Fungal Infections

Tinea faciei:

Fungus affecting the non-beard areas of the face, characterized by inflammatory and non-inflammatory lesions.

Also see: Fungal Infections

Tinea manuum:

Fungus affecting the interdigital and palmar surfaces of one or both palms; the differential diagnosis includes infection caused by nondermatophyte fungi.

Also see: Fungal Infections

Tinea pedis:

Fungus affecting the plantar surface and interdigital spaces of the foot, characterized by both inflammatory and non-inflammatory lesions; the differential diagnosis includes infection by nondermatophyte fungi such as S. hyalinum and S. dimidiatum (H. toruloidea).

Also see: Fungal Infections

Tinea Versicolor:

Tinea Versicolor Tinea versicolor is caused by an overgrowth of yeast. Yeast normally lives in the pores of the skin and grows on areas such as the back, chest, and neck. This overgrowth of yeast results in an uneven skin color that is often scaly and itchy. The yeast appears on the skin as small scaly, pink to white or tan to dark spots that are often scattered over the entire body. On light-skinned people tinea versicolor may be faint or appear as pinkish-brown spots. The fungus generally grows slowly and can cause mild itching. It becomes more noticeable when skin is tanned because the affected spots will not tan.

Tinea versicolor is treated with topical or oral medications. Some over-the-counter treatments include Selsun Blue or Head n Shoulders shampoo, which can be used as a body wash, or topical antifungal creams. Although the yeast is fairly east to treat, the uneven color of the skin may remain unchanged for several months after the yeast has been killed.

Topical:

On the surface of the body.

Topical Corticosteroids:

Millions of people are affected annually with skin diseases that cause marked discomfort, significant morbidity, and rarely death. When skin diseases are extensive or apparent to others, social isolation and difficulty in finding employment may occur. Since the early 1950s, when hydrocortisone cream was found to be an effective antiinflammatory agent, topical corticosteroids have become a mainstay of dermatologic therapy.

Skin diseases amenable to the effects of topical corticosteroids are usually characterized by inflammation, hyperproliferation, and/or immunologic phenomenon. Topical corticosteroids may also be effective in the treatment of skin symptoms, such as burning and itching.

Topical corticosteroids have been used extensively worldwide for the past four decades, resulting in the amelioration of skin disease with very few reports of adverse effects. During this time, products with increased efficacy and accompanying increased potential for adverse effects have been developed. Factors that increase clinical efficacy include enhancement of pharmacologic activity of the compound by altering molecular structure, increasing stratum corneum penetration of the compound, and increasing bioavailability of the compound from the vehicle. At present, attempts are being made to engineer compounds that are locally potent but are rapidly metabolized or otherwise designed to have less potential to cause harmful effects.

Topical Immunomodulators (TIMS):

For over a decade, potent systemic immunomodulators have been used for the treatment of psoriasis and eczema. In the past two years, these medications have been incorporated into topical preparations. When applied topically, these therapies exert their powerful anti- inflammatory effects on the skin without hampering the immune system’s ability to defend itself from bacteria, viruses, and disease. Two topical immunomodulators (TIMs), tacrolimus ointment and pimecrolimus cream, have been approved for the treatment of eczema, a chronic skin condition characterized by itchy, inflamed skin — typically on the insides of the elbows, backs of the knees and the face. These steroid-free treatments are effective in treating eczema without the side effects found with using corticosteroids, medications traditionally used to treat eczema that can cause thinning of the skin, formation of dilated blood vessels, stretch marks, and infection. By specifically interfering with the activation of T-cells, a type of white blood cell in the body responsible for triggering immune responses which contribute to the development of psoriasis, TIMs have been shown to effectively treat this common skin disorder. Studies have also shown that the side effects of topical corticosteroids on the face and other areas in patients with psoriasis can be avoided by treating those areas with TIMs. In addition, the use of TIMs on the eyelids has dramatically reduced the need for topical corticosteroids, which can cause glaucoma and cataracts.

Another breakthrough has been in the use of TIMs to treat actinic keratoses, or AKs, which are known as the early beginnings of skin cancer. Imiquimod, which is approved for the treatment of genital warts, has been shown in recent studies to dramatically improve the treatment of AKs as well as some skin cancers.

Also see: Psoriasis, Eczema, Immunotherapy

Tuberous sclerosis complex (TSC):

A genetic disorder that causes benign tumors to form in many different organs, primarily in the brain, eyes, heart, kidney, skin and lungs. You will see it referred to both as tuberous sclerosis (TS) and tuberous sclerosis complex (TSC). The term TSC is used in scientific literature to distinguish tuberous sclerosis from Tourette's syndrome. The true prevalence of TSC is unknown, but its incidence has recently been estimated to be 1 in 6,000 live births. This means approximately 50,000 individuals in the United States and more than 1 million worldwide have TSC. It occurs in both sexes and in all races and ethnic groups.Because TSC is a genetic disorder, it is not contagious. It is the result of a genetic mutation over which a parent has no control. It is often first recognized in children who have two neurological symptoms—epileptic seizures and/or varying degrees of mental handicap. However, the clinical symptoms of TSC vary greatly and may often not appear until later in life. There are presently no cures and there is no way to predict how severely or mildly an individual may be affected by TSC. Some of the symptoms of TSC include facial angiofibromas (raised, red papules on the face, mainly on the sides of the nose), shagreen patches (patches of normal colored skin on the trunk that have a firmer texture than the surrounding normal skin), fibromas around the nail folds, and “ash-leaf” hypopigmentation. Epileptic seizures are also common.