Low bone mineral density in adult patients with moderate to severe atopic dermatitis

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease commonly treated with topical corticosteroids. The inflammatory nature of this disorder and the use of topical corticosteroids represent potential risk factors for bone loss.

OBJECTIVES: The aim was to assess the prevalence of osteoporosis and osteopenia in adult patients with moderate to severe AD. In addition, the associations between topical/oral corticosteroid use and bone mineral density (BMD) and between disease activity and BMD were studied.

PATIENTS AND METHODS: We studied 125 adult patients with moderate to severe AD. Using dual-energy X-ray absorptiometry, BMD was measured at lumbar spine and hips. The cumulative dose of topical and oral corticosteroids was calculated from pharmacy prescription records. Lifestyle parameters were collected by a questionnaire. Biochemical parameters of bone metabolism and disease activity [serum concentration of thymus and activation-regulated chemokine (TARC) levels] were also measured.

RESULTS: Osteoporosis was documented in six patients (4.8%) and osteopenia in 41 patients (32.8%); 30.4% of the patients had a Z-score <or= -1 (low BMD), with more men (43.8%) than women (16.4%) affected. There was no significant association between low BMD and biochemical parameters of bone metabolism, serum TARC levels and cumulative dose of topical and oral corticosteroids during the 5 years prior to inclusion.

CONCLUSIONS: We document a Z-score <or= -1 in about one-third of predominantly male patients with moderate to severe AD, being independent of the cumulative dose of topical and corticosteroids used within 5 years prior to study. Whether the relatively high prevalence of low BMD is due to the cumulative dose of topical corticosteroids beyond 5 years prior to the study or the chronicity of the underlying inflammatory process or a combination of these, remains to be established.