A novel treatment for idiopathic knuckle pads with cantharidin‐podophylotoxin‐salicylic acid

Abstract

Knuckle pads are benign subcutaneous nodules that appear most frequently on the small joints of the hands. In children, they are often idiopathic, and no universally effective treatment has been reported. We present the case of an adolescent successfully treated with a combination of topical cantharidin -podophylotoxin -salicylic acid. | 545Pediatric Dermatology BRIEF REPORT with absent or peripheral vascularization on Doppler ultrasound.The surrounding soft tissue and tendons are normal. 5The differential diagnosis includes warts, rheumatoid nodules, gouty tophi, Bouchard's and Heberden's nodes, synovial cysts, tumors (giant cell tumor of the tendon sheaths, neurofibromas), and retained foreign bodies. In cases of diagnostic doubt, ultrasound and plain radiographs may be helpful. Magnetic resonance imaging has only been rarely described. 3,5 No effective treatment for KP has been reported in the literature, with behavior modification and psychiatric consultation showing the best results; watchful waiting is usually recommended. 4,5 This case presents an effective treatment alternative for patients with idiopathic KP, with both resolution of the lesions and acceptable cosmetic results. It is a non invasive approach with minimal complications (in this case, only mild pain that was managed with oral medication), which is particularly important considering that most patients are children.

Knuckle pads mimic early psoriatic arthritis

“…Behavior changes and psychiatric support may show results, otherwise watchful waiting is recommended. Some case report described some efficacy of local treatments, such as intralesional fluorouracil or antharidin-podophylotoxinsalicylic acid (12,13).…”

Successful treatment of idiopathic knuckle pads with a combination of high-dose salicylic acid and urea topical keratolytics: A case report

“…Knuckle pads (KPs) or Garrod's nodules are benign subcutaneous fibrotic nodules located in the extensor surface of feet and/or more frequently in finger joints. [1][2][3] Clinically, they are well-circumscribed, non-compressible, freely movable, wartlike lesions involving mostly the dorsal aspect of proximal interphalangeal (PIP) and more rarely metacarpophalangeal (MCP) joints. 4,5 Usually, KPs are painless, asymptomatic (i.e.…”

“…2 In the case of diagnostic doubt, ultrasonography, histology (if sonography is not clear definite), and plain radiograph enhance the information gathering process reducing the risk of misdiagnosis. [2][3][4] On ultrasound, KPs appear as noncompressible, dome-shaped, hypoechoic nodules with absent or peripheral vascularization at Doppler analysis, while histology reveals increased (myo-)fibroblasts proliferation often associated with hyperkeratosis. [1][2][3][4]6 Owing to the absence of specific and effective treatments, a stressful wait-andsee approach is usually recommended.…”

“…[2][3][4] On ultrasound, KPs appear as noncompressible, dome-shaped, hypoechoic nodules with absent or peripheral vascularization at Doppler analysis, while histology reveals increased (myo-)fibroblasts proliferation often associated with hyperkeratosis. [1][2][3][4]6 Owing to the absence of specific and effective treatments, a stressful wait-andsee approach is usually recommended. 1,4 Surgery has also been used, usually without leading to an aesthetic improvement with recurrences, post-operational loss of joint flexibility, scars, and keloids as possible side effects.…”

“…1,3,5 Case reports-based treatments are associated with a low level of evidence and, especially in painless and non-pathogenic conditions, priority should be given to non-invasive methods. Previous reports have shown conflicting results regarding the use of keratolytics in the treatment of KPs, 1,3,7,8 usually without leading to complete resolution. On the contrary, we report here a potential resolutive treatment for idiopathic KPs based on the combination of two common keratolytics, i.e., urea and salicylic acid, administered at high dosages.…”