Treatment of plantar fibromatosis or Ledderhose disease with topical medications.

Effectiveness of topical treatments need take into consideration the disease entity being treated, the potential effect of the pharmacologic agent on the area treated and, importantly, the ability of the agent to reach a therapeutic level in the target tissue.

A challenge, with topical medications, is both the availability and ability to measure the amount of a drug that enters the area to be treated. There are various factors that influence this:

1. Skin thickness.
2. Amount of hyperkeratosis (callous layer).
3. Size of the drug molecule – a smaller molecule may penetrate deeper.
4. Carrier or vehicle – this refers to the substance in which the active ingredient or drug is dissolved in.
5. Level of skin hydration.
6. Shape of the area treated – consider a lesion or fibroma that is relatively flat vs. one that is more spherical. The flatter the lesion, the more surface area exists for potential penetration compared to the more spherical shaped lesion which will have more interior volume relative to surface area.
7. Amount of medication used and frequency of application. There is a limit to the amount of drug penetration per application so increasing the frequency may be more effective than increasing the amount applied.
8. Use of occlusion – application of wraps, tapes can significantly increase absorption of topical medications.

Topical Verapamil

The drug, Verapamil, is a calcium channel blocker, which has been used orally to treat hypertension, cardiac arrhythmia, angina pectoris and a type of headache known as cluster headaches.

Verapamil has been utilized in a topical medication, off label, for the treatment of fibrotic disorders such as Peyronies disease and plantar fibromatosis. The mechanism of action is not fully understood. Fibromas are composed largely of fibrous tissue. Fibroblasts are the cells responsible for the production of the components of fibrous tissue, a process that requires calcium. The components – collagen, fibronectin and glycosaminoglycans can be presumably slowed by use of a calcium channel blocker. PD Labs, a producer of Verapamil gel, has a website that explains this process: https://www.pdlabs.net/plantar_fibromatosis/whatIsTvGel_plantar.html

PD Labs is a compounding pharmacy in San Antonio. Their website is informative and warns consumers to avoid “counterfeit” products.

There is more literature supporting use of topical verapamil gel in Peyronie’s disease that Ledderhose disease. Considering the discussion of factors affecting absorption of topical medications above, one would expect a higher absorption rate on the thinner skin of the penis than the sole of the foot.

My experience is that topical Verapamil is more effective for smaller lesions of Ledderhose disease or when the lesion have been substantially reduced in size by more aggressive treatment. We typically use topical Verapamil as an adjunctive treatment.