Jan 14 (Reuters) - The U.S. Food and Drug Administration approved the expanded use of AbbVie Inc's arthritis drug to treat eczema, a skin disease, the company said on Friday.

The approval of Rinvoq for the treatment of moderate to severe atopic dermatitis, or eczema, was for patients 12 years and older who do not respond to previous treatment or when use of other treatments is not recommended.

Approval for Rinvoq follows significant delays amid concerns over safety https://www.reuters.com/article/abbvie-fda-idUSL4N2OS2WQ of the class of drugs it belongs to, called JAK inhibitors, which block inflammation-causing enzymes known as Janus kinases and target a range of autoimmune diseases.

The FDA last month added its strictest warning to labels of JAK inhibitor drugs from Pfizer, Eli Lilly and AbbVie following the agency's review of Pfizer's Xeljanz, in which initial results from a trial showed an increased risk of serious heart-related problems and cancer in some patients being treated with the drug. (Reporting by Leroy Leo; Editing by Shailesh Kuber)