- A diagnosis of verruca plan (flat warts) is rendered
- Application of tretinoin 0.1%* cream at night. Begin by
applying twice-weekly and increase to daily use as tolerated
- Photoprotection of affected areas
- Follow-up in 6 weeks
*Not FDA approved for treatment of flat warts
Follow-up evaluation strategy
6-week follow-up evaluation:
- Improved (fewer lesions, many resolved, lesions flatter and
smaller in size)
- No evidence of topical retinoid toxicity (erythema,
- Continue application of tretinoin cream
- Follow-up in 6-week intervals (requires total 6 months to
eradicate all lesions)
Verruca plana (flat warts) almost universally involute
spontaneously over several months to years, with no sequelae.
Therapy should be bland and non-scarring, as this is the expected
result from spontaneous involution.
Any treatment plan should start with topical application of
tretinoin 0.1% or 0.25% (cream or gel), which should be applied
twice-daily for 4-6 weeks to induce mild-to-moderate irritation.
This will clear warts in approximately 50% of patients. Alternative
treatments include the use of tazarotene cream 0.1%* twice-daily,
imiquimod cream* 3.75% or 5% daily or, for patients with fewer
lesions, light cryotherapy with or without topical retinoid
Patients should also take steps to prevent the spread of the
lesions. In particular, avoidance of shaving over the affected area
with a razor is recommended until the lesions are cleared, although
use of electric razors may reduce this risk. Patients should also
avoid sun exposure during the summer months, opting to use a
sunblock with UVA and UVB protection on a daily basis.
Subsequent treatment options include 5-fluorouracil 5%* cream
twice-daily (not recommended for infants <6 years or pregnant
women), cantharidin application to larger warts that are fewer in
number (avoid application around the eyes) and immunotherapy.
For immunotherapy, consider dinitrochlorobenzene, squaric acid
dibutylester or diphencyprone, however, be aware that any resulting
dermatitis often looks worse than the warts themselves and may
prove difficult to remedy, as use of steroids to suppress
inflammation are not recommended. Other agents that elicit an
appropriate immune response include intralesional candida antigen,
which may be used adjunctively to the topical therapies mentioned
above. Finally, consider cimetidine (50 mg/kg/day) as an adjunct to
immunotherapy to enhance the response.
Flat warts are commonly confused for inflammatory dermatoses. In
such cases, topical steroids potentially encourage their spread,
especially in patients with atopic dermatitis. They are also
frequently misdiagnosed as acne and in patients who are affected by
both, topical retinoids are an ideal choice.
In general, electrosurgery should be avoided for flat warts, as
scarring may occur, except when the procedure is performed by the
most expert hands. Very gentle, low-voltage (2-5V) hyfrecation can
be attempted to several test lesions, to assess a response and
determine whether undesired sequelae such as scarring or
Finally, it is also worth noting that for certain patients
(those with HIV infection and other forms of immunosuppression),
flat warts can be severe, with many lesions spread over large parts
of the body. In addition, patients with the autosomal recessive
disorder, epidermodysplasia verruciformis, have innumerable flat
warts and a higher incidence of cutaneous carcinomas.
Gibbs S, Harvey I. Topical treatments for warts. Cochrane
Database Syst Rev 2006;3:CD001781.
Kwok CS, Holland R, Gibbs S. Efficacy of topical treatments for
cutaneous warts: a meta-analysis and pooled analysis of randomized
controlled trials. Br J Dermatol 2011;165:233-246.
Loo SK, Tang WY. Warts (non-genital). Clin Evid