Melanoma is a serious skin cancer, which is curable if detected early. Melanoma grows from pigment cells (melanocytes) in the outer layer of the skin and mucous membranes (epidermis). Although melanoma usually starts as a skin lesion, occasionally it occurs in other parts of the body such as the eye, mouth or vagina. Melanoma tends to spread out within the epidermis before moving into the deeper layer of the skin (the dermis). It can occur in adults of any age.

Miliaria is an itchy rash, which arises from obstruction of the sweat ducts. Miliaria is most common in hot, humid conditions. The typical spots develop in skin folds and on the body, especially in areas of friction from clothing. The lesions present as minute red papules, which may be present in very large numbers. Once triggered miliaria can last for several weeks. This is because the plugs which form in the sweat duct openings can only be cast off by the outward growth of the sweat duct cells. This takes several weeks. Treatment cannot influence this process.

Moles are common harmless skin lesions. Moles (melanocytic nevi) may be flat or protruding. They vary in color from pink flesh tones to dark brown or black. The number of moles a person has depends on genetic factors and on sun exposure. Moles begin to grow in infancy but new ones can appear at any age, sometimes in crops. Moles may darken following sun exposure or during pregnancy. During adulthood they often lose their pigmentation, and may disappear altogether in old age.

Molluscum contagiosum is a common viral skin infection resulting in small domed shaped bumps on the skin. Molluscum contagiosum resemble pimples at first. Later, when the spots enlarge, they often have a waxy, pinkish look with a small central pit. Sometimes there are as many as a hundred spots on one individual. Molluscum contagiosum can be spread to susceptible individuals by direct skin contact. It is harmless and never turns cancerous. It generally heals without scarring. Usually the lesions disappear within 9-12 months, rarely lasting longer than two years. They do, however, tend to be more numerous and last longer in children who also have atopic eczema.

Morphea is a localized scarring of the skin characterized by a violet colored rash that evolves into an ivory colored firm depression. There is an associated loss of hair follicles and sweat glands. In Europe such lesions have been associated with a lyme disease-like infection.

A mucous or myxoid cyst arises from degeneration in the connective tissue overlying the joints of the fingers. It may connect with the joint at the end of the finger. The cyst has a smooth shiny surface and is commonly found at the base of the nail. It often causes a groove in the nail, a few millimeters across which extends the length of the nail. The cyst's size may vary. Jelly-like sticky fluid may be expressed from it (sometimes tinged with blood).

Fungal infection of the nails is known as "onychomycosis". It is increasingly common with increased age. It rarely affects children. Tinea unguium may affect one or more toenails and/or fingernails and most often involves the great toenail or the little toenail. It can present in one or several different patterns: Lateral onychomycosis, presenting with a white or yellow opaque streak at one side of the nail; Subungual hyperkeratosis, presenting with scaling under the nail; Superficial white onychomycosis, presenting with flakey white patches and pits appear on the top of the nail plate; and proximal onychomycosis, presenting with Yellow spots in the half-moon.

Nevi is also known as a Mole. Moles are common skin lesions. Moles (correctly called melanocytic or pigmented nevi) may be flat or protruding. They vary in color from pink flesh tones to dark brown or black. The number of moles a person has depends on genetic factors and on sun exposure. Moles begin to grow in infancy but new ones can appear at any age, sometimes in crops. Moles may darken following sun exposure or during pregnancy. During adulthood they often lose their pigmentation, and may disappear altogether in old age.

Contact allergic dermatitis to nickel may develop at any age. Once this nickel allergy has occurred, it persists for many years, often life-long. Nickel allergy is more common in women, probably because they are more likely to have pierced ears than men, although this is changing. The degree of allergy varies. Some people develop dermatitis (also called eczema) from even brief contact with nickel-containing items, while others break out only after many years of skin contact with nickel. Some people develop intermittent or persistent eczema on their hands and feet. It is usually a blistering type of eczema, known as pompholyx.

Nummular dermatitis, also know as discoid eczema, is a skin condition which can occur at any age. It can affect any part of the body particularly the lower leg. One or many patches appear, and may persist for weeks or months. The majority of patches are round or oval, hence the name "discoid" or "nummular" dermatitis, which means coin or disc-shaped dermatitis. They can be several centimeters across, or as small as two millimeters. The skin between the patches is usually normal, but may be dry and irritable. Discoid eczema may be extremely itchy, or scarcely noticeable. When the patches clear, they may leave marks for some weeks of months, which are darker or sometimes paler than the normal skin tone. In most cases no specific allergy can be found. Discoid eczema does not run in families, and unlike atopic dermatitis, it is not associated with asthma. It does not result from food allergy. It is not infectious to other people, although bacteria sometimes secondarily infect it.

Occupational or therapeutic contact with mineral oils or tar can result in comedones and inflamed hair follicles (folliculitis). Excessive oil on the skin can result in small pustules with a red halo in affected areas. Commonly, the lesions are seen on the forearms and thighs. The follicles may obviously be plugged with oil. The pustules may be sterile or contain the harmless skin bacteria, Staphylococcus epidermidis. They may be painless or painful. Topical creams or ointments containing tar can also cause oil folliculitis. These are used for the treatment of eczema and psoriasis.

Fungal infection of the nails is known as "onychomycosis". It is increasingly common with increased age. It rarely affects children. Tinea unguium may affect one or more toenails and/or fingernails and most often involves the great toenail or the little toenail. It can present in one or several different patterns: Lateral onychomycosis, presenting with a white or yellow opaque streak at one side of the nail; Subungual hyperkeratosis, presenting with scaling under the nail; Superficial white onychomycosis, presenting with flakey white patches and pits appear on the top of the nail plate; and proximal onychomycosis, presenting with Yellow spots in the half-moon.

This condition is a variant of psoriasis in which groups of sterile pustules occur in crops on one or both hands and/or feet. They are associated with thickened, scaly, red skin, which easily develops painful cracks (fissures). The condition varies in severity and may persist for many years. It is not known what causes exacerbations or remissions. Palmoplantar pustulosis is not infectious to other people and does not influence one's general health. However the discomfort can be considerable, interfering with working and leisure activities. Walking for prolonged periods may cause exacerbations on the feet. If the palms are involved, manual activities may be uncomfortable, and injuries may aggravate the disorder. Certain occupations are therefore inadvisable for affected individuals. It is much more common in those who smoke (or have smoked in the past), sometimes runs in families and rarely occurs before adulthood.

Papular urticaria is a skin condition, which most commonly affects children, and consists of crops of very itchy red bumps, 0.2 - 2 cm in diameter. The bumps may develop a fluid-filled blister up to one centimeter in diameter. They are most often on the legs and other uncovered areas such as forearms and face but sometimes they are scattered in small groups all over the body.

Pemphigoid ( bullous pemphigoid ) is an auto-immune disease in which the body produces antibodies to the basement membrane (the underlying layer of the skin) resulting in tense blisters. This condition tends to occur in older patients and occasionally related to medications.

Pemphigus (pemphigus vulgaris) is an auto-immune disease in which the body produces antibodies to the skin cells in the epidermis resulting in flacid blisters of the skin and mucous membranes. This may result in serious complications and requires the use of oral immunosupressive drugs, including prednisone.

Some people develop a rash because their skin is sensitive to sunlight; this is known as Photosensitivity. Patients may not associate their skin complaint with the light. It is not always the bright summer sun, which is responsible; some people also react to winter daylight, and very sensitive subjects may even be affected by fluorescent lamps indoors. Photosensitivity occurs for a variety of reasons. Some known causes include: Medicines taken internally. Chemicals, fragrances or plant materials in contact with the skin. A metabolic disorder such as Porphyria. Autoimmune disease (self-allergy), such as Lupus Erythematosus.

Phototherapy is a treatment that consists of using light UVA and/or UVB range to treat numerous skin conditions. Disoeders commonly treated this modality include psoriasis, cutaneous t-cell lymphoma, and eczema.

Pitted keratolysis is a skin condition affecting the soles of the feet. It affects those who sweat profusely (hyperhidrosis) especially if they wear occlusive shoes or boots for long periods. The condition is caused by Corynebacteria. Either the forefoot or the heel or both become white with clusters of punched-out pits. The appearance is more dramatic when the feet are wet. Very rarely, the fingers are similarly affected. There is a variant of pitted keratolysis where there are more diffuse red areas on the soles.

Pityriasis alba is a common skin condition affecting children and occasionally young adults. Several round or oval slightly scaly pink patches appear, leaving pale marks when the redness has faded. Pityriasis alba patches are more apparent in summer, especially in dark-skinned children, because they don't tan as well as the surrounding skin. Pityriasis alba is a mild form of dermatitis of unknown cause. It will clear up after a few months, or in some cases persist two or three years. The color gradually returns completely to normal.

Pityriasis rosea is a common viral infection of the skin which is characterized by pink to red oval rose petal shaped lesions on the torso, arms, and legs sparing the hands, feet and face. Typically, there is an intial "herald patch" which precedes the generalized rash. There maybe some itchiness associated with it and it can be treated with steroid creams and light therapy. It typically occurs only once in a lifetime.

Pityrosporum folliculitis is a condition where the yeast, pityrosporum (also called Malassezia furfur), infiltrates the hair follicles and multiplies, creating an itchy, acne-like eruption. The condition affects young to middle-aged adults of either sex. It is associated with a tendency to seborrhoeic eczema or severe dandruff. The rash consists of tiny itchy dome-shaped pink papules with an intermingling of small pustules. The spots are located mainly on the upper back, shoulders and chest. Occasionally, spots are found on the forearms, back of the hands, lower legs and face.

Plant dermatitis is an eruption caused by skin contact with certain plants. The rash may take various forms but is generally itchy, red and swollen. Common offending plants include poison ivy, Peruvian lily, and English primrose. Some plants only cause a rash if the sun is shining on the skin at the same time (phytophotodermatitis). Plant dermatitis is not contagious and the blister fluid does not spread the rash. The rash appears between four hours and 10 days after exposure to the plant, depending on individual sensitivity and the amount of contact. Occasionally, new eruptionscan appear after treatment has begun due to blood stream spread of the allergy to other areas.

Pompholyx is also known as, vesicular hand and/or foot eczema. It is a common type of eczema affecting the hands (cheiropompholyx), and sometimes the feet (pedopompholyx). The condition may be mild with subtle peeling, or severe with large blisters and cracks. The first (acute) stage presents with tiny blisters (vesicles) deep in the skin, associated with itching and a burning feeling. The more chronic stage manifests with more peeling, cracking, or crusting. Some patients will have mostly one stage, and some patients will have mostly the other. Some times both stages occur at the same time. Secondary infection with Staphylococcal bacteria is not infrequent. The result is pain, redness, swelling and crusting or pustules. Pompholyx of the hands is aggravated by contact with irritants such as water, detergents and solvents. Contact with these agents must be avoided as much as possible and protective gloves worn.

Porphyria cutanea tarda is the most common type of porphyria. Prophyria cutanea tarda (PCT) is due to a defective enzyme in the liver (uroporphyrinogen decarboxylase) involved in synthesis of the red pigment in blood cells (heme). The result is an increase in porphyrins in the skin, resulting in photosensitivity i.e. the skin is damaged by light. Affected individuals develop fragile skin, sores (erosions), blisters (vesicles and bullae), and tiny cysts (milia) on the sun-exposed areas i.e. the back of the hands and the forearms. They may notice that they sunburn easily. Some people develop mottled brown patches around the eyes and increased facial hair. Occasionally the skin becomes hardened (sclerodermoid) on the neck, face or chest. There may be small areas of permanent baldness (alopecia) or ulcers. There is a genetic predisposition to PCT. It generally begins in mid-adult life after exposure to certain chemicals, which increase the production of porphyrins (precursors of heme) in the liver.

Pseudofolliculitis barbae is also known as shaving rash or razor bumps. It is a foreign-body inflammatory reaction surrounding ingrown facial hair, which results from shaving. The problem occurs more commonly in individuals with curly hair.

Psoriasis is a disorder of the skin, which typically consists of red plaques covered by silvery-white scales. These red scaly patches are usually found on the elbows, knees, lower back, and scalp. When psoriasis involves the groin, armpits, and genital area and beneath the breasts it tends to be less scaly and have a glazed appearance. Psoriasis infrequently affects the face. It does not cause scarring and rarely results in hair loss. Psoriasis is common, affecting approximately 2% of adults. Its exact cause is unknown but the result is skin, which grows about seven times quicker and thicker than usual. It is thought to be due, at least in part, to an abnormal immune reaction against some component of the skin. Genetic factors play a part; only some families develop the condition, and about half those affected know of someone else in the family with it. The rash often seems to start after some sort of trigger factor. This may be emotional stress, skin injury (cuts and scratches for example), a streptococcal sore throat, hormones (it often first occurs at puberty), or rarely, certain medications. These factors should be avoided whenever possible by people with psoriasis. Psoriasis is not an allergy, nor is it infectious to others.

Dermatology Dictionary     |      Helpful Links

               

Privacy Notice || Forms