Apremilast and Moderate to Severe Chronic Hand Dermatitis

Hand dermatitis is one of the most common skin disorders encountered by dermatologists. Chronic hand dermatitis (CHD) is often due to allergic contact dermatitis (ACD) or irritant contact dermatitis (ICD) and has a 1-year and lifetime prevalence of up to 10% and 15%, respectively, in the general population. On average, the disease affects patients for about 7 to 11 years. Patients with ACD show an increase in cytokines produced from T helper (Th)1 and Th17 cells, including (interleukin) IL-17 and IL-23, which are also implicated in the pathogenesis of psoriasis. Apremilast, a small molecule phosphodiesterase-4 (PDE-4) inhibitor, has demonstrated clinical efficacy and tolerability in the treatment of psoriasis and psoriatic arthritis, likely through the blockade of IL-17, IL-23, and several other pro-inflammatory mediators. Therefore, it may provide an effective treatment option for other Th1 and Th17-mediated disease (such as CHD due to ACD and ICD), which share a common immunologic pathway with psoriasis. Investigators hypothesize that apremilast has the ability to decrease disease severity in patients with moderate-to-severe CHD that is either secondary to psoriasis, or occurring in patients with an atopic or allergic past medical history. Hence, investigators have designed a pilot study involving CHD patients who attend the dermatology clinic at the George Washington Medical Faculty Associates (GW MFA) in order to assess the efficacy and safety of apremilast treatment for the treatment of moderate to severe CHD. The objectives are as follows: Primary objective: 1\. To evaluate the efficacy of Apremilast 30mg twice daily administered as monotherapy in the treatment of moderate-to-severe CHD as assessed by improvement of the Physician Global Assessment (PGA). Secondary objectives: 1. To evaluate the safety and tolerability of Apremilast 30mg twice daily as assessed by monitoring adverse events, laboratory values (CBC, CMP), and physical examination. 2. To evaluate CHD lesion time to response (TTR) as assessed by Modified Total Lesion Symptom Score (mTLSS). 3. To evaluate the patient's perception of CHD severity improvement as assessed by the Patient Global Assessment (PaGA). 4. To evaluate the patient's health-related quality of life as assessed by the Dermatology Life Quality Index (DLQI) questionnaire a measurement of the patient's subjective symptoms. STUDY ENDPOINTS Primary endpoint: 1\. Proportion of patients achieving a 2 point decrease in Physician Global Assessment (PGA) at the end of the study. Secondary endpoints: 1. Proportion of patients achieving Physician Global Assessment (PGA) score of 0 (clear) or 1 (almost clear) at end of study. 2. Change in mTLSS, patient global assessment, and DLQI scores from baseline to end of study. 3. Photographic improvement of CHD from baseline to end of study.