What Caused the Palmar Keratoderma?

Case Report
A 23-year-old healthy man presented with yellow thickening on the palmar surface of his third, fourth, and fifth digits of both hands located at the metacarpophalangeal joints.  Since age 17, he regularly exercised in the gym and performed deadlifts with weights. Cutaneous examination shows hyperkeratosis of the ventral distal hand just proximal to the third, fourth, and fifth fingers (Figure 1). 

What Is The Diagnosis?

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Diagnosis: Weightlifter’s Calluses

Keratoderma is a thickening of the skin that commonly affects the palms and soles. It can be classified as congenital or acquired, and sometimes it is associated with sports. There are several methods available to manage the symptoms of keratoderma.

Clinical Presentation 
Calluses present as thickening of the skin (Figures 1 and 2). They typically occur at sites of friction, irritation, or pressure. Often, they are located on the fingers and hands or toes and feet. 

Differential Diagnosis 
Congenital keratoderma. Keratoderma presents as a congenital or an acquired condition. Congenital keratodermas present at birth or shortly after; they may present as isolated lesions or diffuse hyperkeratosis of palms or soles.^1-3 Congenital keratoderma may be associated with extracutaneous conditions such as metabolic disorders, deafness, and impaired sexual development.²

Acquired keratoderma. Acquired keratoderma has several possible etiologies (Table).³ They include primary skin conditions such as dermatitis and psoriasis. They also can be a cutaneous manifestation of mite infestation, spirochete infection, or viral infection in patients with scabies, syphilis, or warts, respectively. In addition, some women develop thickening of palms when they begin menopause.³  

Malignancy-associated acquired palmar keratoderma can be a primary manifestation of the cancer in patients with mycosis fungoides. In addition, it can be a paraneoplastic syndrome in patients with either acrokeratosis paraneoplastica or tripe palms. Also, skin cancer, such as squamous cell carcinoma, can present with hyperkeratotic palmar lesions. 

Sports-related dermatoses. Sports, such as weightlifting, can result in calluses on the participant’s palms. Repetitive friction between the athletes’ hands and the bars containing weight results in the thickening of that area. Indeed, a similar sports-related dermatosis, referred to as surfer’s nodules or athlete’s nodules, occurs on the extensor distal legs of surfers, secondary to repetitive friction between their legs and the surfboards.^4-6 

Weightlifter’s calluses are a sports-related acquired keratoderma. Corns can also be observed in athletes.^7-9 However, unlike corns, calluses are not well demarcated and usually do not cause pain.^10,11  

Pathology
Microscopically, there is hyperkeratosis of stratum corneum. Other features can include parakeratosis, acanthosis, and dermal lymphocytic inflammation.³ The dermis may also exhibit increased collagen bundles in athletes with sports-related nodules.⁴ 

Management
The treatment of keratoderma may involve paring the area with either a pumice stone or a razor.¹¹ Topical keratolytics, such as lactic acid, salicylic acid, and urea, can also be applied to remove excess tissue.³ Recently, selenium sulfide was shown to effectively manage keratoderma.¹² Avoiding recurrent palmar fissures and wearing gloves for protection can also be effective.¹³

Our Patient 
Our patient realized the association between his weightlifting and the development of his palmar keratoderma, and he deferred treatment. Similar to athlete’s nodules on the legs of surfers, the presence of calluses on the palms of weightlifters is considered to reflect an achievement of excellence in weightlifting. Hence, our patient wanted to continue to demonstrate his accomplishment in the sport. 

Conclusion
Weightlifter’s calluses are an acquired type of keratoderma observed in athletes who participate in the sport. The lesions are typically found bilaterally on the palmar surface just proximal to one or more fingers. Several modalities are available for treatment. However, most weightlifters are proud of the lesions and their significance as reflections of accomplishment in the sport.

Mr Tang is a student at the University of California, San Diego, School of Medicine in San Diego, CA. Dr Cohen practices at San Diego Family Dermatology in National City, CA.

Disclosures: The authors report no relevant financial relationships.  

References
1.  Guerra L, Castori M, Didona B, Castiglia D, Zambruno G. Hereditary palmoplantar keratodermas. Part I. Non-syndromic palmoplantar keratodermas: classification, clinical and genetic features. J Eur Acad Dermatol Venereol. 2018;32(5):704-719. doi:10.1111/jdv.14902

2. Guerra L, Castori M, Didona B, Castiglia D, Zambruno G. Hereditary palmoplantar keratodermas. Part II: syndromic palmoplantar keratodermas - diagnostic algorithm and principles of therapy. J Eur Acad Dermatol Venereol. 2018;32(6):899-925. doi:10.1111/jdv.14834

3. Patel S, Zirwas M, English JC 3rd. Acquired palmoplantar keratoderma. Am J Clin Dermatol. 2007;8(1):1-11. doi:10.2165/00128071-200708010-00001

4. Emer J, Sivek R, Marciniak B. Sports dermatology: part 1 of 2 traumatic or mechanical injuries, inflammatory conditions, and exacerbations of pre-existing conditions. J Clin Aesthet Dermatol. 2015;8(4):31-43. 

5. Cohen PR, Eliezri YD, Silvers DN. Athlete’s nodules: sports-related connective tissue nevi of the collagen type (collagenomas). Cutis. 1992;50(2):131-135.

6. Cohen PR, Eliezri YD, Silvers DN. Athlete’s nodules. J Am Acad Dermatol. 1991;24(2 Pt 1):317-318. doi:10.1016/S0190-9622(08)80631-7

7. Bergfeld WF. Dermatologic problems in athletes. Clin Sports Med. 1982;1(3):419-430. 

8. Houston SD, Knox JM. Skin problems related to sports and recreational activities. Cutis. 1977;19(4):487-491. 

9. Richards RN. Calluses, corns, and shoes. Semin Dermatol. 1991;10(2):112-114. 

10. Phillips S, Seiverling E, Silvis M. Pressure and friction injuries in primary care.

Prim Care. 2015;42(4):631-44. doi:10.1016/j.pop.2015.07.002

11. Bannerman E, Stevenson JH. Dermatology issues in sports. Curr Sports Med Rep. 2017;16(4):219-220. doi:10.1249/JSR.0000000000000372

12. Cohen PR, Anderson CA. Topical selenium sulfide for the treatment of hyperkeratosis. Dermatol Ther (Heidelb). 2018;8(4):639-646. doi:10.1007/s13555-018-0259-9

 13. Muller SA. Dermatologic disorders in athletes. J Ky Med Assoc. 1976;74:225-228.