When A Runner Presents With Painful Plantar Lesions
Recurrence after incomplete excision may occur. For this reason, it is essential to follow up with patients and ensure close observation for possible recurrence and the development of new lesions in other areas of the body.26
What You Should Know About Prevention And Treatment
Currently, there is no one completely effective treatment for porokeratosis plantaris discreta. Accordingly, the condition often requires ongoing management to provide relief of the pain caused by the lesions.
Initial treatment includes debridement of the lesion, removing the overlying hyperkeratotic tissue and taking care to remove as much of the deep nucleus as possible.
Adhesive padding to offload the area will also help to alleviate any discomfort associated with the lesion. A temporary insole constructed out of Plastazote can assist in pressure reduction and assist in determining if there is a role for custom foot orthotics. If one is using custom foot orthotics, mark the lesions to fabricate an offloading accommodation on the orthotic to decrease pressure. This lessens both the pain associated with the lesion and the rate at which the lesion grows.
One can apply a compound of topical salicylic acid 40% in white soft paraffin to the lesion in a pad with an aperture cut out to localize the medication to this area. Remove the pad after 48 hours and debride the lesion, which is now macerated.
Another option in the management of these lesions is intralesional injection therapy, which physicians have utilized for a number of years.27,28 Dockery reports that porokeratosis plantaris discreta responds well to 4% alcohol sclerosing injections.29 He recommends using a 1 mL tuberculin syringe and a 5/8-inch, 25-gauge needle to inject a total of 0.25 mL to 1.0 mL of 4% sclerosing solution at a 45 degree angle to the lesion. The amount of the solution one uses will depend upon the size of the lesion.
Repeat this at weekly intervals for up to seven injections. By the third injection, one will usually see a dramatic change in the lesion, according to Dockery.29 If the lesion has responded, no further treatment is necessary. If one has performed three injections and the lesions have regressed or not responded, terminate the procedure and recommend alternative treatments.
The weekly intervals seem to be relatively important and longer intervals between injections may delay the end results. Again, once the local anesthesia wears off, there may be considerable burning or pain at the injection site that may last for several hours. You can reduce this discomfort by applying cool foot soaks or ice to the area. Analgesics, especially aspirin, may also help reduce the pain.29
Risks of this procedure include short-term nerve pain and occasionally an erythematous reaction around the site of the injection. However, these effects are short lived and resolve on their own.
Cryosurgery offers another option in the management of porokeratosis plantaris discreta. Limmer treated 21 lesions of porokeratosis plantaris discreta cyrosurgically in 11 patients.30 He removed the blister roof two weeks after cryosurgery with re-treatment of any residual lesion. He reported this was an effective method for removal of these lesions without scarring, noting a cure rate of 90.5 percent.
Like many hyperkeratotic related problems involving the plantar aspect of the foot, there is no definitive treatment that consistently results in the eradication of porokeratosis plantaris discreta. Ongoing conservative care is required to allow the patient to function with limited discomfort.
Dr. Haverstock is a Fellow of the American Society of Podiatric Dermatology. He is the Division Chief and Assistant Clinical Professor of Surgery in the Division of Podiatric Surgery within the Department of Surgery with the University of Calgary Faculty of Medicine in Calgary, Alberta.
For further reading, see “When Injection Therapy Can Help Relieve Painful Lesions” in the June 2002 issue of Podiatry Today or “Differentiating Non-Pigmented Tumors In The Lower Extremity” in the December 2009 issue.