PDE4 inhibitors are used to treat certain medical conditions that involve inflammation. Some PDE4 inhibitors help treat chronic obstructive pulmonary disease (COPD), while others help manage eczema, psoriasis, and psoriatic arthritis. These medications work by blocking the enzyme phosphodiesterase-4 (PDE4), which helps reduce inflammation in your body. PDE4 inhibitors come in different forms, including oral tablets and topical creams. Examples include roflumilast (Daliresp) for COPD, apremilast (Otezla) for psoriasis and psoriatic arthritis, and Eucrisa (crisaborole) for eczema. These treatments help manage your condition effectively.