The Role of Janus Kinase (JAK) and Voltage-gated Sodium Channels (Nav) on Pain and Itch

It is well known that itch and pain have many communalities in terms of pathways and molecules involved. Therefore, it is very important to investi-gate different substances that work against both pain and itching. The substances delgocitinib and lidocaine have both been shown to relieve various types of pain. We therefore assume that these creams will be also able to relieve itching. The purpose of this trial experiment is therefore to investigate the effect of delgocitinib, lidocaine and their combination on experimentally induced itching.

Inclusion Criteria: * Healthy men and women * 18-60 years * Speak and understand English Exclusion Criteria: * Pregnancy or lactation * Drug addiction defined as any use of cannabis, opioids, or other drugs that may cause addiction. * Previous or current history of neurological, dermatological (e.g., AD, psoriasis, etc.), immunological, musculoskeletal, cardiac disorder or psychiatric diagnoses that may affect the results (e.g., neuropathy, muscular pain in the upper extremities, anxiety, depression, schizophrenia, etc.) * Moles, wounds, scars, or tattoos in the area to be treated or tested * Current use of medications that may affect the trial such as antihistamines and painkillers * use of antihistamines should be discontinued 72 hours before the experiment and all topical agents and emollients should be discontinued 24 hours before the experiment). * Use of systemic and topical corticosteroids * Previous traumatic experience of an electrical accident * Application of moisturizing lotion of the volar site of the forearms (24 hours before study start) * Skin diseases * Consumption of alcohol or painkillers 24 hours before the study days and between these * Acute or chronic pain and itch * Known allergy/intolerance to lidocaine/phenytoin/mepyramine * Participation in other trials within 1 week of study entry (4 weeks in the case of pharmaceutical studies) * Lack of ability to cooperate