Essential Insights On Treating Psoriatic Lesions In The Lower Extremity

Author(s): 
M. Joel Morse, DPM

Matching The Best Treatment For The Type Of Psoriasis

Palmoplantar psoriasis tends to be resistant to conventional therapies and may last for several years. Treatment options remain unsatisfactory for patients with palmoplantar psoriasis and palmoplantar pustular psoriasis.44 Topical treatments are usually ineffective but, depending on the area of involvement of the sole/foot, one can try the topical combination of Dovonex and betamethasone as a first-line treatment. Systemic therapy with oral retinoids and psoralen plus ultraviolet A light phototherapy is frequently required although it rarely leads to remission.45 Biologics may also be effective in the treatment of sole psoriasis.

   One of my patients had total resolution of her severely disabling plantar psoriasis with one year of phototherapy that was coupled with six months of etanercept. She is still plaque free at the time of this publication.

   The treatment options for nail psoriasis include topical or interlesional steroids, photochemotherapy, topical fluorouracil, topical calcipotriol, topical anthralin, topical tazarotene, topical cyclosporine, avulsion therapy, and systemic therapy for severe cases. If all 10 nails are involved, do not try topical therapy and instead educate the patient or make a referral to a dermatologist who treats psoriasis. One should also remember the close association of nail disease and psoriatic arthritis, and contemplate a referral to a rheumatologist.

   High-potency corticosteroid solution or ointment under occlusion with cellophane wrap at bedtime can improve nail psoriasis. A recent study tested a water-soluble nail lacquer, which contains hydroxypropyl chitosan (Vitivia, Innocutis), horsetail extract (Equisetum arvense) and methylsulfonylmethane (DMSO2).46 This product, which recently became available, was effective in strengthening the nails and reducing fragility and roughness in brittle nails. At the end of treatment, patients showed a 72 percent reduction in pitting, a 66 percent reduction in leukonychia, a 63 percent reduction in onycholysis and a reduction of 65 percent in the NAPSI score in comparison to baseline.

   Another study also reviewed the use of tacalcitol ointment (a vitamin D3 analog) and a new formulation containing 8% clobetasol-17-propionate in a colorless nail lacquer vehicle that has produced good results for the control of nail psoriasis.46

   Intralesional steroids with the use of triamcinolone acetonide suspension of 2.5 mg/mL into the proximal nail fold are very helpful for nail matrix psoriasis (e.g., pitting, ridging, leukonychia). One may administer this medication every four to six weeks. Clinicians would spray the proximal nail fold first with a refrigerant spray for anesthesia and give the injection with a 30-gauge needle. I have found that digital anesthesia makes the steroid injection less painful.

   At present, there are three systemic medications (methotrexate, retinoids and cyclosporine) that clinicians most commonly use for nail psoriasis. A recent study found that a low dose of methotrexate (5 mg) once a week successfully treated severe nail psoriasis involving all 20 nails.47

   One can perform surgical avulsion therapy for psoriatic nail disease when other treatments have failed. During surgery, one can cauterize or surgically remove the matrix to prevent regrowth of the nail. Whether this “traumatic” event will result in worsening of the condition is unknown.

   Dr. Morse is the President of the American Society of Podiatric Dermatology. He is a Fellow of the American College of Foot and Ankle Surgeons, and the American College of Foot and Ankle Orthopedics and Medicine. Dr. Morse is board certified in foot surgery. He is on the Podiatric Residency Educational Committee at the Washington Hospital Center.

References

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