Dermal Lesions

Dermal Lesions
A dermal lesion refers to any change in the normal condition of the skin. Dermal lesions, or skin lesions, can be grouped into two categories: primary and secondary lesions. A primary dermal lesion is an abnormality that has been present from birth or acquired later in life. Secondary lesions occur when a primary lesion changes as a result of being manipulated, treated, or in relation to the progression of any underlying condition or infectious process, such as candidiasis, herpes zoster, herpes simplex or impetigo.

Primary Lesions

• Vesicle: fluid-filled blister less than 5mm in diameter; elevated above the level of the skin with well demarcated borders.
• Bulla: a large vesicle (greater than 5mm in diameter).
• Pustule: similar in appearance to a vesicle or bulla, but contains purulent material.
• Macule: red, brown, tan or white in color; defined borders; flat.
• Nodule: firm to touch; elevated above the level of the skin; easily palpable. Nodules may involve all layers of the skin.
• Wheal: irregularly shaped area of edematous skin; may come and go; may appear white, pink or red in color; often elevated above the level of the skin; often irregular in size or shape.
• Plaque: elevated above the level of the skin; irregular in shape; firm to the touch; flat; rough in texture.
• Telangiectasia: small dilated blood vessels that occur near the surface of the skin.

Secondary Lesions

• Crust: contains dried blood, serum or exudate; elevated slightly above the level of the skin; can be either large or small in area.
• Scale: keratinized cells that grow one on top of another; may be flakey and easily removed; irregular in size; dry or oily; thin or thick; may be white or cream-colored.
• Excoriation: scratches that may break the skin, often caused by fingernails.
• Lichinification: epidermis that becomes thickened and rough due to chronic scratching or rubbing of the skin.
• Atrophy: thin, fragile skin; occurs frequently in elderly people and people using topical steroids for extended periods.
• Scarring: normal skin that has been replaced by discolored and fibrous scar tissue.
• Ulcer: See: Arterial Ulcers, Diabetic Neuropathic Foot Ulcers, Stage I, Stage II, or Stage III or IV Pressure Ulcers, Venous Insufficiency Ulcers.

Etiology

Dermal lesions can be caused by any of a large variety of factors. The tendency to develop benign lesions such as freckles, birthmarks and moles is often inherited. Viral, bacterial, or fungal infection of the skin is often the culprit in cases of acquired dermal lesions. In cases of contact dermatitis, allergic reactions to environmental factors can lead to dermal lesions. In the extreme case of diseases like chicken pox and small pox, the characteristic dermal lesions that form as a result are often used to recognize the disease. The same is true for many skin cancers that have the characteristics or shape.

Complications

Complications of dermal lesions depend predominantly on the initial cause of the defect. The most common complication is permanent change to the condition of the skin, such as discoloration or scarring, however, complications of certain lesions can be life-threatening.

Treatments & Interventions

Treatment of dermal lesions depend heavily on the type and cause of the lesion. Treatments range from topical applications for less severe cases, to oral medications in the case of systemic infections. In some cases, surgical removal of the lesion may be required, which is often accomplished either by curettage, cryotherapy, or laser therapy.

References

Brooks I. Secondary bacterial infections complicating skin lesions. J Med Microbiol. 2002;51(10):808-812. http://jmm.sgmjournals.org/content/51/10/808.full. Accessed May 31, 2018.

Williams G, Katcher M. Primary Care Dermatology Module Nomenclature of Skin Lesions. The University of Wisconsin Madison. http://www.pediatrics.wisc.edu/education/derm/text.html. Accessed May 31, 2018.