{
  "required_concepts": [
    "water-induced finger and toe wrinkling",
    "stratum corneum water absorption contributes but is insufficient",
    "sympathetic autonomic vasoconstriction reduces digital pulp volume",
    "denervation or sympathetic nerve injury evidence",
    "time temperature medium and individual variation",
    "drainage-network or wet-grip adaptation hypothesis",
    "mixed evidence and failed or limited replication",
    "normal transient recovery after drying and warming",
    "aquagenic wrinkling of palms boundary",
    "no neurological or cystic-fibrosis self-diagnosis"
  ],
  "required_sources": [
    "Mark Changizi and colleagues",
    "Kyriacos Kareklas and Tom Smulders",
    "German and colleagues or another study reporting no clear grip advantage"
  ],
  "practical": [
    "dry and warm hands",
    "protect skin barrier during frequent immersion",
    "use suitable gloves",
    "do not time wrinkles as a nerve self-test"
  ],
  "safety": [
    "persistent or one-sided wrinkling",
    "pain numbness weakness discoloration wounds or infection",
    "very rapid pronounced painful or itchy aquagenic wrinkling needs professional assessment",
    "do not self-diagnose cystic fibrosis"
  ]
}