Apremilast and Moderate to Severe Chronic Hand Dermatitis

Inclusion Criteria: 1. Adults between the ages of 18-79 years. 2. Must be in general good health (except for disease under study) as judged by the Investigator, based on medical history, physical examination, clinical laboratories, and urinalysis. (NOTE: The definition of good health means a subject does not have uncontrolled significant co-morbid conditions). 3. Clinical diagnosis of CHD as defined by hand dermatitis for more than 6 months or more than 2 flares within 12 months. 4. Moderate to severe CHD, defined as a PGA score of 3 (moderate) or 4 (severe). 5. History of AD, childhood eczema, ACD, or ICD. 6. History of disease that is unresponsive to conventional treatment (i.e. corticosteroids, calcineurin inhibitors, phototherapy) for CHD. Lack of response to treatment is defined as an unsatisfactory outcome (no response, transient response to ongoing treatment or lack of tolerability) based on patient history and medical records. 7. No other active skin diseases or acute skin infections dominating the clinical picture. 8. Females of childbearing potential (FCBP)† must have a negative pregnancy test at Screening and Baseline. While on investigational product and for at least 28 days after taking the last dose of investigational product, FCBP who engage in activity in which conception is possible must use one of the approved contraceptive§ options described below: Option 1: Any one of the following highly effective methods: hormonal contraception (oral, injection, implant, transdermal patch, vaginal ring); intrauterine device (IUD); tubal ligation; or partner's vasectomy; OR Option 2: Male or female condom (latex condom or nonlatex condom NOT made out of natural \[animal\] membrane \[for example, polyurethane\]; PLUS one additional barrier method: (a) diaphragm with spermicide; (b) cervical cap with spermicide; or (c) contraceptive sponge with spermicide. † A female of childbearing potential is a sexually mature female who 1) has not undergone a hysterectomy (the surgical removal of the uterus) or bilateral oophorectomy (the surgical removal of both ovaries) or 2) has not been postmenopausal for at least 24 consecutive months (that is, has had menses at any time during the preceding 24 consecutive months). § The female subject's chosen form of contraception must be effective by the time the female subject is randomized into the study (for example, hormonal contraception should be initiated at least 28 days before randomization). Exclusion Criteria: 1. \<18 or \>79 years of age. 2. Evidence of tinea mannum involving the hands (verified by positive fungal culture). 3. Evidence of an active untreated infection (bacterial, fungal, viral etc) involving the hands at baseline visit. 4. Use of topical corticosteroids on the hands within 2 weeks prior to baseline visit. 5. Use of topical calcineurin inhibitor (tacrolimus, pimecrolimus) on the hands within 2 weeks prior to baseline visit. 6. Use of crisaborole on the hands within 2 weeks prior to baseline visit. 7. Use of light based treatments on the hands within 1 month prior to baseline visit. 8. Use of systemic therapy (cyclosporine, azathioprine, methotrexate, alitretinoin) within 4 weeks prior to the start of study medication OR 5 pharmacokinetic / pharmacodynamics half-lives (whichever is longer). 9. Inability to make study visits or anticipated poor compliance. 10. Pregnant females or nursing mothers. Eligible women of reproductive age will be required to adhere to strict pregnancy prevention measures, which includes a negative urine pregnancy test at screening and subsequent visits. 11. History of Tuberculosis, Hepatitis B, C, or HIV. 12. Any history or evidence of a medical comorbidity that would make the subject, in the opinion of the investigator, unsuitable for the study. 13. Active substance abuse or a history of substance abuse within 6 months prior to Screening. 14. Other than disease under study, any clinically significant (as determined by the Investigator) cardiac, endocrinology, pulmonary, neurologic, psychiatric, hepatic, renal, hematologic, immunologic disease, or other major disease that is currently uncontrolled. 15. Life threatening illness that would interfere with the subject's ability to complete the study. 16. Any condition, including the presence of laboratory abnormalities, which would place the subject at unacceptable risk if he/she were to participate in the study. 17. Prior history of suicide attempt at any time in the subject's life time prior to screening or randomization, or major psychiatric illness requiring hospitalization within the last 3 years. 18. Malignancy or history of malignancy, except for: 1. Treated \[i.e., cured\] basal cell or squamous cell carcinomas of the skin with no evidence of recurrence within the previous 5 years. 2. Treated \[i.e., cured\] cervical intraepithelial neoplasia (CIN) or carcinoma in situ of cervix with no evidence of recurrence within the previous 5 years. 19. Use of any investigational drug within 4 weeks prior to randomization, or 5 pharmacokinetic/pharmacodynamic half-lives, if known (whichever is longer). 20. Prior treatment with apremilast.