While palmar wrinkling after immersion in water is a common phenomenon, the hallmark of aquagenic keratoderma is the rapid development of the wrinkling. In unaffected individuals, palmar wrinkling occurs about 11 minutes after immersion in water, whereas those affected by aquagenic keratoderma experience wrinkling in as little as 2 minutes of immersion in water. Resolution of symptoms can occur within minutes of removing the hands from water but may take hours for complete recovery. A clinical diagnosis of aquagenic keratoderma can be made by immersing the patient's hand in water and checking for palmar wrinkling after 5 minutes. Waiting over 10 minutes to check for wrinkling may give false positives.
Histologic examination of affected areas of the palm show hyperkeratosis of the stratum corneum with dilation of the ostia of eccrine ducts. Biopsies must be conducted on skin before resolution of symptoms, as the skin may appear normal on histology if the skin changes are not present at the time of collection.
Dating back to the 1970s, aquagenic palmar wrinkling was described in the literature in association with cystic fibrosis (CF), and it was not until 30 years later that aquagenic keratoderma was recognized as a distinct disorder. The condition is strongly associated with CF. While cases are described in individuals without diagnosed CF, genetic tests on these individuals with aquagenic keratoderma often reveal that they are carriers of one of the CF gene mutations.
Aminoglycoside medications and cyclooxygenase 2 inhibitors have been implicated in triggering aquagenic keratoderma. If a patient has a positive family history for CF or CF carrier status or a past medical history of a potentially CF-associated condition (such as pancreatic insufficiency), performing genetic testing to assess for CF gene mutations may be prudent.
Despite the association with CF, the pathophysiology of aquagenic keratoderma remains unclear. The initial hypothesis proposed that the palmar symptoms result from a high sweat chloride content attributable to CF transmembrane conductance regulator dysfunction that increases the water-binding capacity of keratinocytes. A more recent theory suggests that aquagenic keratoderma in CF patients is due to dysfunction of transient receptor potential cation channel subfamily V member 4, a protein channel that activates a signal cascade to reduce cell volume swelling from osmosis in unaffected patients. A dysfunction in this protein channel would reduce effective regulation of water through eccrine ducts.
Others hypothesize that aquagenic keratoderma occurs because of weak eccrine duct walls. It also is proposed that water immersion stimulates sympathetic nerve fibers, causing vasoconstriction of the palms and digits and ultimately leading to palmar wrinkling and the associated parasthesias.
Although the palmar eruptions are self-resolving, one report found that the use of ivacaftor, a pharmacologic potentiator of the CF transmembrane conductance regulator, in CF patients with aquagenic keratoderma resulted in decrease in both sweat chloride content and in palmar wrinkling after immersion in water. Other treatments used to prevent the development of palmar wrinkling and discomfort in aquagenic keratoderma include aluminum chloride and onabotulinumtoxinA. Both treatment types have variable results.
This case and photo were submitted by Marianna Blyumin-Karasik, MD, of Precision Skin Institute, Davie, Fla., and Lauren Crouse of Brody School of Medicine, East Carolina University, Greenville, N.C.
Dr. Bilu Martin is a board-certified dermatologist in private practice at Premier Dermatology, MD, in Aventura, Fla. More diagnostic cases are available at edermatologynews.com. To submit a case for possible publication, send an email to firstname.lastname@example.org.
Please note: Illustration(s) are not available due to copyright restrictions.
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|Title Annotation:||Make the Diagnosis|
|Author:||Martin, Donna Bilu|
|Date:||Mar 1, 2017|
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