60
Flat warts
Flat warts are barely raised, flesh-colored to brown, flat-topped papules. They typically occur on the face, dorsum of the hands, or shins, and can be spread by shaving.
Grouped pink flat-topped papules along a line that suggests autoinoculation.
Multiple small flat-topped papules on the vermilion.
Filiform wart on the lower lip. This type of wart like flat warts is typical on the face in children. Snipping the warty skin or freezing with liquid nitrogen are potential treatments.
DESCRIPTION
Flat warts are benign, cutaneous hyperproliferations due to infection with human papillomavirus. Common subtypes are types 3 and 10.
HISTORY
• Common in children and young adults. • Flat warts spread in a local region often through mildly traumatized skin, such as within an area of shaving. • Duration may be lengthy; flat warts may be very resistant to treatment. • Generally located in cosmetically important areas where aggressive, scarring treatment procedures must be avoided. • Immunocompromised patients often have a protracted course.
PHYSICAL FINDINGS
• Pink, light brown, or light yellow papules are slightly elevated and flat-topped. They vary in size from 0.1–0.3 cm. May be few or numerous and often occur grouped or in a line as a result of spread from scratching. • Typical sites are forehead, back of hands, chin, neck, legs. • Typically asymptomatic.
TREATMENT
• If sparse numbers of lesions, a salicylic acid preparation may be applied daily directly to each lesion. This treatment is limited by irritation. Other options: • Tretinoin cream 0.025%, 0.05%, or 0.1% applied at bedtime over the entire involved area. The frequency of application is adjusted to produce fine scaling and mild erythema. Treatment may be required for weeks or months. • Liquid nitrogen or a very light touch with an electrocautery needle may be performed for quick results. Flat warts may not respond to cryotherapy, even after many treatment sessions. • Imiquimod 5% cream (Aldara) applied to affected skin at night. Decrease frequency of application if excessive irritation. Treatment may be required for weeks. • Applied once or twice a day for 3–5 weeks, 5-fluorouracil cream 5% (Efudex) may produce dramatic clearing of flat warts. Persistent hyperpigmentation may follow the use of 5-fluorouracil and is minimized by applying it to individual lesions with a cotton-tipped applicator. • Inform patients that flat warts are easily spread within areas of shaving. Discourage shaving over affected skin. • Unlike common warts, the face is a common location for flat warts.
