Warts and all

When viral warts aren’t so simple

Warts are usually a straightforward consultation. Diagnose, treat, move on.

This week a patient’s warts were different. I saw a 70-year-old man with eight warts on his fingers, present for several years and resistant to treatment. He’d already had multiple topical therapies and even curettage — which I tend to think of as the nuclear option for warts — but the warts had recurred after treatment.

At that point, the question isn’t what they are (clinically and dermoscopically they were warts), but why they were persisting.

I tend to think about wart treatment as working with the immune system. Warts can sit unchanged for years, and then suddenly the immune system recognises them and - BANG- they disappear within days. Many treatments people try — duct tape, salicylic acid, cider vinegar — are essentially attempts to irritate the skin enough to trigger that immune response. Prescription treatments such as imiquimod (Aldara) or 5-fluorouracil (Efudix) aim to stimulate the immune response directly.

But in this consultation my focus shifted from treatment to host factors: why was this patient not mounting an effective immune response?

We discussed screening for possible immunodeficiency. I arranged blood tests including full blood count, diabetes screening, HIV testing, and a paraprotein given his age. If these return normal but suspicion remains, lymphocyte subsets would be the next step.

Management options were narrowing. Aldara or Efudix alone would be reasonable, but I felt he might benefit from something more proactive. During my registrar years I presented a case series using combination therapy — gentle cryotherapy followed by imiquimod. The rationale is the cryotherapy initiates irritation and an initial immune response, followed by Aldara, which sustains the inflammation. I treated each lesion with 10 seconds of cryotherapy, followed by Aldara five times per week for six weeks.

Take-home: when warts are numerous, longstanding, and treatment-resistant — especially in older adults — it’s worth stepping back. Sometimes the key issue isn’t the virus, but the host.

I’ll be interested to see how he responds and will share an update in due course.