Lesions are any morbid changes in the structure or function of tissues due to
injury or disease. They may be life-threatening; that is, indicating tuberculosis, cancer,
or other diseases. They can cause disturbances of normal skin functions; represent
findings that are significant of internal diseases such as hepatitis or endocrine problems;
can cause severe itching and/or pain; and can cause psychological distress and social
problems because of unsightly appearance.
a. Primary Lesions. These are the most important to recognize and if
necessary, to biopsy. They are also the earliest changes that appear. Macule, papule,
nodule, tumor, wheal, plaque, vesicle, bulla, and pustule are all considered primary
(1) Macule (see figure 4-2). This is a flat, localized change in the skin's
color. The area may be small or large, less than 1 cm in diameter. Macules occur in
many shapes and colors and is nonpalatable. Some examples of macules are freckles,
flat moles, tattoos, and the rashes of rubella and rubeola.
Figure 4-2. Macule.
(2) Papule (see figure 4-3). This is a solid, elevated lesion, about 0.5 cm to
1 cm or less in diameter. Their borders and tops may assume various forms. Some
papule lesions can occur in insect bites, acne, psoriasis, and atopic eczema.
Figure 4-3. Papule.