Characterization of Chronic Hand Eczema

Inclusion criteria

• All subjects:
• Male or female subjects aged 18 to 65 years, inclusive, at the time of consent.
• Subject is willing to participate and is capable of giving informed consent. Note: Consent must be obtained prior to any study-related procedures.
• Subject must be willing to comply with all study procedures and must be available for the duration of the study.
• CHE subjects only:
• Subject has at least a 6-month history of CHE before Screening (information obtained from medical chart or subject's physician, or directly from the subject).
• Subject has moderate to severe CHE as defined by an IGA score of ≥3 at Screening and Day 1.
• Subject has CHE covering ≥0.25% of BSA on palmar surface of hands at Screening and Day 1.
• Subjects has CHE that can be categorized in one of the following CHE subtypes at Day 1:
• Atopic hand eczema (without wet-work or excessive contact with irritants)
• Irritant contact hand eczema without atopic disease
• Hyperkeratotic hand eczema without atopic disease
• Vesicular hand dermatitis without atopic disease
• Allergic contact hand eczema without atopic disease
• Idiopathic hand eczema without wet-work, excessive contact with irritants, atopic disease, hyperkeratotic morphology, allergic contact hand eczema and vesicular hand eczema.
• Subjects with only AD:
• Subject has clinically confirmed diagnosis of active atopic dermatitis, according to Hanifin and Rajka criteria.
• Subject has at least a 6-month history of AD and had no significant flares in AD for at least 4 weeks before Screening (information obtained from medical chart or subject's physician, or directly from the subject).
• Subject has moderate to severe AD as defined by a vIGA-AD score of ≥3 at Screening and Day 1.
• Subject has AD covering ≥0.5% of BSA at Screening and Day 1.
• Subject has an AD lesion covering ≥0.25% of BSA on the forearm at Screening and Day 1.Healthy Volunteers only:
• Subject is in good general health, according to the investigator's judgment based on medical history and physical examination.

Exclusion criteria

• All subjects:
• Subject has a history of skin disease or presence of skin condition that, in the opinion of the investigator, would interfere with the study assessments.
• Subject has used systemic antibiotics within 2 weeks prior to Day 1.
• Subject has used topical antibiotics within 1 week prior to Day 1.
• Subject has used topical products containing urea or salicylic acid within 1 week prior to Day 1.
• Subject has received any marketed or investigational biological agent within 12 weeks or 5 half-lives (whichever is longer) prior to Day 1.
• Subject is currently receiving a nonbiological investigational product or device or has received one within 4 weeks prior to Day 1.
• Subject has had excessive sun exposure, is planning a trip to a sunny climate, or has used tanning booths within 4 weeks prior to Day 1. Use of sunscreen products are recommended when exposure cannot be avoided.
• Subject is a female who is pregnant or who is planning to become pregnant during the study.
• CHE subjects only:
• Subject has clinically infected chronic hand eczema on hands and/or wrists.
• Subject with suspected or proven hand eczema protein contact dermatitis.
• Subject has used doxepin within 1 week prior to Day 1.
• Subject has used hydroxyzine or diphenhydramine within 1 week prior to Day 1.
• Subject has used any topical medicated treatment that could affect CHE within 1 week prior to Day 1, including, but not limited to, topical corticosteroids, topical retinoids, crisaborole, calcineurin inhibitors, tars, antimicrobials, medical devices, and bleach baths.
• Subject has used alitretinoin, isotretinoin, acitretin or other systemic retinoids within 4 weeks before Day 1, or has not completely recovered from its side effects.
• Subject has used systemic treatments (other than biologics) that could have an impact on CHE less than 4 weeks prior to Day 1 (eg, calcineurin inhibitors, methotrexate, cyclosporin, hydroxycarbamide \[hydroxyurea\], azathioprine), or systemic steroids (including oral or injectable corticosteroids).
• Note: Intranasal corticosteroids, eye or ear drops containing corticosteroids, and inhaled corticosteroids for stable medical conditions are allowed.
• Subject has used dupilumab within 12 weeks prior to Day 1.
• Subject has received any UV-B phototherapy (including tanning beds) or excimer laser within 4 weeks prior to Day 1.
• Subject has had psoralen-UV-A (PUVA) treatment within 4 weeks prior to Day 1.
• Subjects with only AD:
• Subject has clinically infected AD.
• Subject has AD lesion on hand and/or feet at screening or Day 1.
• Subject has received an intravenous immunoglobulin (IVIg) therapy within 12 weeks prior to Day 1.
• Subject has used doxepin within 1 week prior to Day 1.
• Subject has used hydroxyzine or diphenhydramine within 1 week prior to Day 1.
• Subject has used any topical, medicated treatment that could affect AD within 1 week prior to Day 1, including, but not limited to, topical corticosteroids, crisaborole, calcineurin inhibitors, ruxolitinib, tars, antimicrobials, medical devices, and bleach baths.
• Subject has used systemic treatments (other than biologics) that could affect AD less than 4 weeks prior to Day 1, including, but not limited to, retinoids, calcineurin inhibitors, methotrexate, cyclosporine, hydroxycarbamide (hydroxyurea), azathioprine, oral/injectable corticosteroids, baricitinib, upadacitinib, and abrocitinib.
• Subject has used dupilumab within 12 weeks prior to Day 1.
• Subject has received any UV-B phototherapy (including tanning beds) or excimer laser within 4 weeks prior to Day 1.
• Subject has had PUVA treatment within 4 weeks prior to Day 1. Note: Intranasal corticosteroids and inhaled corticosteroids are allowed. Eye and ear drops containing corticosteroids are allowed.
• Subject has used tralokinumab within 12 weeks prior to Day 1.
• Healthy Volunteers only:
• Subject has history of atopic dermatitis, allergic rhinitis, or asthma.