Aquagenic wrinkling of the palms after brief immersion to water test as a screening tool for cystic fibrosis diagnosis

Abstract

Background: Aquagenic wrinkling of the palms (AWP) is an excessive and early palmar wrinkling occurring after Brief Immersion to Water (BIW), and has been reported as a frequent finding among cystic fibrosis (CF) patients.

Objectives: To evaluate and assess the diagnostic performance of BIW test as an initial screening tool for CF diagnosis.

Methods: We measured AWP in CF patients, CF-heterozygotes (CF-het) and normal controls. The AWP parameters of palmar wrinkling, oedema, papules, pruritus and pain were assessed at 3, 7 and 11 min after a BIW test was performed for all the participants. Statistical analyses explored the progression of AWP in time for the three groups and assessed the diagnostic performance of BIW test as a diagnostic screening tool for CF.

Results: A total of 250 individuals (100 CF patients, their 50 CF-het parents, 100 healthy controls) were included in the analysis. The average age in years (mean ± SD) was 10.4 ± 4.0 for CF, 35.9 ± 6.1 for CF-het and 10.5 ± 4.0 for controls. The rate of positives for AWP at 3 min among CF patients, CF-het and controls was 68%, 8% and 0%, respectively (P < 0.01). Kaplan-Meier analysis showed a clear trend towards earlier appearance of all five parameters in the direction controls < hetCF < CF (P values <0.01). The best diagnostic performance in detecting between CF patients and non-CF was achieved by the presence of papules and wrinkling at 7 min (sensitivity/specificity: 94.0%/98.3% and 100.0%/92.0%, respectively).

Conclusions: A strong association between AWP and CF was detected. AWP after BIW could be elicited easily and possibly can be used as an initial screening tool to assess if an individual with symptoms and signs that raise the likelihood of CF is a CF patient.