NIH
Zebra of the Week: Aquagenic palmoplantar keratoderma
Aquagenic palmoplantar keratoderma is a rare condition affecting the palms of the hands. It's characterized by the appearance or worsening of a palmar eruption, following brief exposure to water. The palmar eruption is made up of small, white or shining lesions that can conjoin into plaques. The feet are unaffected.
Symptoms include a burning pain and a tightening sensation in the palms, as well as hyperhidrosis. There are two variants. Most commonly, it's a temporary and recurrent condition that appears after submersion in water, known as the 'hand in the bucket sign,' that gets better within minutes to hours of drying. A less common variant is characterized by persistent lesions that are worsened after water submersion.
The cause of aquagenic palmoplantar keratoderma is unknown, but likely relates to sweating. Several studies have found that it's present in about 40% to 84% of cystic fibrosis patients and also in carriers, which suggest that it may be caused by genetic changes in the CFTR gene. It's more often found in young women. Besides cystic fibrosis, it's also seen in wasting (marasmus) and nephrotic syndrome and also with the use of aspirin and other drugs such as rofecoxib and celecoxib.
Source:
NIH. (Accessed 2025, May 23). Aquagenic palmoplantar keratoderma. https://rarediseases.info.nih.gov/diseases/12991/aquagenic-palmoplantar-keratoderma