superimposed scale that produces bleeding when removed. Skin lesions of a
secondary syphilis are copper colored. Violet papules are typical of lichen planus skin
lesions, and the papules of lichen sclerosis are whitish. Rounded, red, bluish-red, or
brownish-red papules characterize the skin disease pyogenicum.
Figure 3-4. Papule.
(3) Nodule. A nodule (figure 3-5) is a solid, elevated lesion that extends
deeper into the dermis than the papule. A nodule is greater than 0.5 cm in diameter but
less than 2 cm and may or may not be elevated above the level of the surrounding skin.
Examples of nodules include keratinous cysts, small lipomas (benign tumors composed
of mature fat cells), fibromas (benign tumors derived from fibrous connective tissue),
some types of lymphoma (malignant diseases usually in the lymph nodes), and a variety
of neoplasms (abnormal, excessive, and uncontrolled multiplication of cells forming a
mass or new growth of tissue). Nodules are often an indication of systemic disease and
can result from inflammation, neoplasms, or metabolic deposit in the dermis or
subcutaneous tissue. For example, nodules are present in late syphilis, tuberculosis,
and roundworm infestation. Sometimes local agents can produce nodules--foreign-
body reactions, milker's virus, or tick bites.
Figure 3-5. Nodule.