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Chapters

0:00 Introduction
0;40 colour and pigmentation
1;22 morphology
4;38 distribution
5;22 configuration



The skin is the largest organ in the body and is sensitive to a variety of conditions. Doctors recommend getting skin checked once a year as skin conditions are the first sign of trouble for many serious medical problems. The ability to accurately identify and classify a range of skin signs and symptoms remain necessary in examining the skin. The doctor will need to look for and identify skin color and pigmentation if skin lesions are present they are examined in reference to their morphology, anatomic distribution, and configuration.
COLOR AND PIGMENTATION
Pigmentation is the coloring of the skin. Before any inspection is carried out, it is important that the doctor note the color of the skin.
• Red spots result from many different inflammatory diseases and may indicate an underlying skin condition such as eczema or allergies.
• Orange skin results from a benign condition of carotene deposition after a high ingestion of beta-carotene
• Yellow skin results from jaundice
• Violet skin may result from vasculitis or cutaneous hemorrhage
• Grayish or blue skin also called pallor result from a lack of oxygenated blood to the area that is discolored
MORPHOLOGY
The doctor is required to assess the form and structure of the lesion. Is it flat, raised above the skin or depressed below the skin?
Primary lesions are damages in the skin caused directly by the disease process
• Macule - flat, non-palpable area of altered skin usually 1.5cm in diameter
• Patch - flat, non-palpable area of altered skin usually 1.5cm in diameter
• Papule – raised palpable lesion with distinct borders 0.5cm in diameter
• Nodule - raised palpable lesion that may extend into the dermis, epidermis and subcutaneous tissue usually 0.5cm in diameter
• Plaque – flat, palpable lesion that is raised or depressed with either a well-defined or poorly defined borders usually 1cm in diameter
• Vesicle(blister) - small, raised lesions filled with clear fluid usually 0.5cm in diameter
• Bulla - small, raised lesions filled with clear fluid usually 0.5cm in diameter
• Wheal – raised oedematous papule or plaques caused by dermal edema
• A pustule- raised lesion that contains pus usually 0.5cm in diameter
• Papilloma – benign wart-like lumps on the skin
• Telangiectasia –dilated blood vessels visible on the skin surface
• Petechiae – a tiny, circular, lesions on the skin surface caused by a minor bleed from broken capillary blood vessels.
• Purpura – purpled-colored lesions on the skin due to hemorrhage from small blood vessels
• Ecchymosis – a discoloration on the skin caused by a blood leak from a broken capillary into surrounding tissues under the skin.
• Burrow – linear lesions that are produced by the infestation of the skin and formation of tunnels.
Secondary lesions are an evolution of primary lesions or occur as a result of external forces such as trauma or infection.
• Scale – visible fragments of stratum corneum as it detaches from the skin
• Crust – rough surface made up of dried serum, blood, or pus
• Excoriation- traumatized skin caused by scratching or rubbing
• Lichenification – thickening of the epidermis seen with exaggeration of normal skin due to chronic rubbing or scratching of an area.
• Fissure – a sharply-defined linear tear of skin in the epidermis due to dryness
• Erosion - slightly depressed area of skin with a partial or total loss of the epidermis
• Ulcer- defect in the skin with loss of epidermis and some part of the dermis
• Scar- areas of fibrosis that changes and replace normal skin after an injury
• Atrophy- thinning or the absence of the epidermis
• Stria- commonly known as stretch marks
DISTRIBUTION
Distribution describes how the lesion is spread out on the body. This is helpful when examining skin lesions as they often have characteristics locations.
• Symmetric - affecting both the right and left sides of the same region
• Asymmetric – affecting one side and not the other
• Extensor- affecting extensor surfaces such as elbows, knees
• Flexural- involving skin flexures
• Localized- limited to some part of the body
• Generalized – widely distributed over the body with no exception of any major area of the skin
• Photodistribution- affecting areas that receive the most exposure to the sun
CONFIGURATION
Configuration refers to the shape and outline of the skin lesions. The arrangement of multiple lesions or shape of an individual lesion can help during an examination of the skin
Linear lesions take the shape of a straight line
Annular lesions are rings with central clearing
Reticulated lesions have a lacy or networked pattern