A little introduction of dermatology
Anatomy of skin
Types of skin lesion
- Primary skin lesions
- Secondary skin lesions
- Special skin lesions
Primary skin lesions
Macule
A definite are of skin in which the skin color has change from the normal skin color. This area is neither higher of lower than the surrounding skin area. These flat, discolored spot are either hypopigmented or hyperpigmented. Varied in size less than one milliliter. Color ranging in as coffe color with milk (in Albright's syndrome), blue-black (urticaria) or white (leprosy). A pacth skin lesion is defined as small-size macule.
Macule
Papule
A solid, elevated lesion usually 0.5cm tp 1cm or less in diameter. Many skin disease start with papules; warts, psoriasis, syphilis. Different papules has different color based on the skin diseases. For example, skin lesion on syphilis are copper coloured and lichen sclerosis are whitish.
Papule
Nodule
A solid, elevated lesion that extends deeper into the dermis than the papule. A nodule is greater than 0.5cm in diameter but less than 2cm and may or may not be elevated above the level of the surrounding skin. Example of nodule is fibromas, small lipomas, and keratinous cyst. Nodules are often indication for systemic disease and can result from inflammation, neoplasms, or metabolite deposit in the dermis or subcut tissue.
Nodule
Wheal
A red swelling skin itchy lesion and localized edema. Lesion is usually cause by an allergic reaction, insect bites or reaction from drugs. Hives, urticaria and mosquito bites are examples.
wheals
Tumor
An elevated, solid lesion greater than 2cm. Tumor, a general term for any mass, benign or malignant is sometimes used to indicate large nodule.
Tumor
Plague
A patch of closely grouped papules more than in (1 cm) across. Lesions are rough in texture and color brown, red, or pink. The size is larger than 1 cm. Rubeola and psoriasis are examples.
A plague
Vesicle/bulla
A raised lesion that is less than in (0.5 cm) across. Lesions are round or oval in shape with thin mass filled with serous blood or clear fluid. Herpes simplex, burn blister and early chicken pox are examples of vesicle. Bullae are another example of vesicle that is more than in (5 mm) across. Lesions are cause by chemical burn, exposure to sunlight, insect bites or viral infection.
Vesicles
Pustule
A raised vesicle or bulla lesion filled with pus. Infection is the primary cause. Acne vulgaris, impetigo and boils are examples.
Pustule
Secondary skin lesions
Crust
Are dried effete masses of exudation such as fluid, blood, or pus or damage skin surface; as, for example, the crusts of impetigo, of eczema, and of the pustular and ulcerating syphilodermata
A skin crust
Scales
Scales are dry, laminated, epidermal exfoliations; as, for example, the scales of psoriasis, ichthyosis, and eczema.
Scales
Fissures
Fissures are linear cracks or wounds, involving the epidermis, or epidermis and corium; as, for example, the cracks which often occur in eczema when seated about the joints, the cracks of chapped lips and hands.
Ulcers
Ulcers are rounded or irregularly-shaped and sized loss of skin and subcutaneous tissue resulting from disease; as, for example, the ulcers of syphilis and of cancer.
Skin ulcer
Erosion
—Area of skin denuded by complete or partial loss of epidermis.
Erosion
Scar
A fibrous healing of a wound that replaces the normal dermis and epidermis that have been damaged.
Skin scar
Keloid
Occurs in an area of injury or just arises spontaneously. It is a smooth overgrowth of fibroblastic tissue.
A keloid
Atrophy
Skin atrophy is a thinning and wrinkling of the epidermis often seen in aged. Caused by overstretching and weakening of the elastic tissues of the skin
Skin atrophy
Special skin lesions
Comedo (blackhead)
Blackhead develops when sebaceous glands become because of accumulated serum.
Blackhead
Milia (whitehead)
Occurs when a sebaceous duct is blocked with horny material (cosmetics).
Milia
Telangiectasia
A dilated superficial blood vessels. Can be found around the nail bed, on the face and trunk
Telangiectasia
Abscess
Localized collection of pus usually caused by bacterial infection in tissues, organs or confined spaces.
Petechiae
Small haemorrhage under the skin
Petechiae
Ecchymosis
Rupture vein (bruise) caused by escape blood from injured blood vessels
Skin ecchymosis
Maceration
Softening of solid tissue by soaking. The tissue turns white and breaks down easily.
Maceration
Burrow
A tunnel in the epidermal layer of the skin cause by parasite (eg: scabies mite)
Skin burrow
Excoriation
Excoriation (scratching)
Carbuncle
Staph infection of with multiple tracts (several furuncles) that extend to subcut tissues. Usually develop in adjoining hair follicle, developing slowly than one furuncle and sometimes accompanied by fever and prostartion. The infection causes pus to be produced and drain from furuncles.
Carbuncle
Folliculitis
Caused by staph aureus, folliculitis is a superficial or deep bacterial infection and irritation of the hair follicle. The lesion is made up of a superficial pustule or inflammatory nodule surrounding a hair.
Skin folliculitis
Wen
Common type of epidermal cyst, a sebaceous cyst, found on the scalp or scrotum. The sebaceous cyst containing follicular, keratinous, and sebaceous material. When punctured the contents of cyst are found to be cheesy, often fetid formed of epithelial debris and greasy materials with soft keratin present.
Ps: This is not a complete article. More references is needed to understand the skin lesions.
Sources: secondary skin lesion; articlesbase.com. Types of primary skin lesions;health.wikinut.com, skin lesions; vickywebworld.org, Skin lesion; integrated publishing www.tpub.com
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1 comments:
Great information. Thank you for sharing
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