no muscle weakness - PEDSUniversity.org

The Case of the Knarley Knuckles
J.A. Schneider, D.O.
Phil E. Buster
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Phil is a 12 year-old with a URI and
“Oh, by the way, what can you do about
my fingers?”
He has a 2-year history of totally
asymptomatic swellings over his
knuckles.
Past medical history is totally
noncontributory
Phil E. Buster
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Phil denies:
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Any form of trauma
including karate and
martial arts
Any habits that could
be causative
Joint swellings
Sun/photo intolerance
Phil E. Buster (continued)
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Physical examination:
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Firm, hypopigmented pads over the
proximal interphalangeal joints of both
thumbs and several fingers
no evidence of hypertrophic scarring
no subcutaneous nodules nor joint swelling
without heliotrope
no muscle weakness
Phil’s funny knuckles...
Whoa! Those are some knarley knuckles…
to the max!
Fleshy, hypopigmented pads over
the interphalangeal joint
Okay, take a minute,
think this through...
Do you have a
differential
diagnosis in mind?
…and your
final answer is?
Answer: Knuckle Pads
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Described by Garrod in
1893, but can be found
in Renaissance paintings
and Michelangelo’s
statue of David in
Florence
Answer: Knuckle Pads
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May be primary (autosomal dominant)
or secondary to trauma or can be
occupational
Usually asymptomatic, but a syndrome
with leukonychia and deafness has
been reported
Differential Diagnosis:
Knuckle Pads
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Scars/Keloid
Epidermolysis
Bullosa Acquisita
Epidermolysis
Bullosa Dystrophica
Callus
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Granuloma Annulare
Rheumatoid Nodules
Digital Fibroma
Xanthomas
Dermatomyositis
Erythropoetic
Protoporphyria
References
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Reaves, C.: Knuckle Pads. J. Am. Acad.
Derm. Vol. 13 #4 pp 40A - 41A, 1985.
Paller, A. and Herbert, A.: Knuckle
Pads in Children. AJDC Vol. 140 pp
915-917, 1986
References
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Knuckle pads: does knuckle cracking play an
etiologic role? Pediatr Dermatol 2000 NovDec;17(6):450-2 Peterson CM; Barnes CJ;
Davis LS Department of Internal Medicine,
Section of Dermatology, Medical College of
Georgia, Augusta, Georgia 30904, USA.
Knuckle pads--a forgotten skin condition:
report of a case and review of the literature.
Cutis 1996 Apr;57(4):241-2 Guberman D;
Lichtenstein DA; Vardy DA Dermatology
Department, Hadassah University Hospital,
Jerusalem, Israel.
References
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Familial leuconychia, knuckle pads, hearing loss,
and palmoplantar hyperkeratosis: an additional
family with Bart-Pumphrey syndrome. J Med
Genet 1994 Jan;31(1):68-71 Ramer JC; Vasily
DB; Ladda RL Department of Pediatrics, Milton
S Hershey Medical Center, Pennsylvania 17033.