Biopsy of the skin for direct epidermal fluorescent studies is indicated in the investigation of certain disorders such as lupus erythematosus, blistering disease, and vasculitis. Skin biopsies are also used to confirm the histopathology of skin lesions, to rule out other diagnoses (e.g., cancer, herpes simplex, and psoriasis), and to monitor the results of treatment. Techniques used to obtain a skin biopsy include a shave biopsy, which removes a small section of the top layer of skin, a punch biopsy, which removes a section of skin containing deeper layers, or an excisional biopsy, which removes an area of abnormal skin and a portion of normal skin.

1. Obtain a 3- to 6-mm punch biopsy, shave biopsy, or excisional biopsy specimen of involved or uninvolved skin. Scraping smears and aspirates also may be obtained. Take care not to crush the specimen.

2. Check with your laboratory for specific guidelines for specimen handling.

3. See Chapter 1 guidelines for intratest care.

1. Biopsy of skin shows the lesions of discoid lupus erythematosus as a bandlike immunofluorescence of immunoglobulins and complement components. Similar findings in a biopsy of normal skin are consistent with SLE and may be used to monitor the results of treatment.

2. In blistering diseases such as pemphigus and pemphigoid, in which circulating antibodies may not be present, a lesion may show intercellular epidermal antibody of pemphigus or basement membrane antibody of pemphigoid.

3. Additional conditions that may be identified include basal cell or squamous cell carcinoma, skin infection, or psoriasis.

Pretest Patient Care

1. Explain the purpose and procedure of the skin biopsy. Tell the patient that local anesthesia will be used.

2. Ensure that a signed consent is in the patient’s medical record.

3. Follow guidelines in Chapter 1 for safe, effective, informed pretest care.

Normal

A descriptive interpretative report of the skin biopsy is made.