O/E: Symmetrical hyperkeratosis of both elbows. Knees perfectly normal as is the remainder of his cutaneous exam. He is moderately overweight.
Clinical Images:
Comment: I suppose we all see this entity on frictional sites, but rarely name it. The patient denies rubbing or scratching the area but was observed to lean on his elbows. A similar problem has been reported (see reference 1. below). I recommended starting with 5% Keralyt gel twice daily and may add tretinoic acid. I propose that this type of hyperkeratosis can follow pressure on bony prominences, such as is seen on the foreheads of devout Muslims who pray 5 times a day (2). Prayer marks in Muslims appear to be more common in diabetics (3). The patient described in this VGRD post could well have the metabolic syndrome. I wonder if this might be important. I'd appreciate your thoughts.
Reference:
1. Frictional asymptomatic darkening of the extensor surfaces.
Krishnamurthy S, Sigdel S, Brodell RT. Cutis. 2005
Jun;75(6):349-55.
Abstract: Frictional asymptomatic darkening of the extensor
surfaces (FADES), also known as hyperkeratosis of the elbows and knees, is
commonly seen by dermatologists but has never been well characterized. Patients
present with uniform, asymptomatic, brown darkening over the extensor surfaces
of the elbows and knees with minimal scaling. Both frictional stress and family
history may play a role in the pathogenesis of this condition. The results of
cutaneous biopsy specimens typically reveal hyperkeratosis, acanthosis, and
mild papillomatosis with minimal inflammation. Keratolytic agents such as
lactic acid and urea cream along with avoiding frictional stress can be
effective in the management of this condition. We describe a series of cases of
FADES and its etiology and management options.
Comment in: Frictional asymptomatic darkening of the
extensor surfaces. [Cutis. 2007]
2. Prayer marks. Abanmi AA et. al. Int J Dermatol. 2002
Jul;41(7):411-4.
Prayer marks (PMs) are asymptomatic, chronic skin changes
that consist mainly of thickening, lichenification, and hyperpigmentation, and
develop over a long period of time as a consequence of repeated, extended
pressure on bony prominences during prayer. PubMed.
3. Prayer Marks in Immigrants from Bangladesh with Diabetes Who
Live in Greece. Papadakis G, et. al. J
Immigr Minor Health. 2016 Feb;18(1):274-6. PubMed.