Leeds Dactylitis Index

The Leeds Dactylitis Index (LDI) is an instrument to measure the activity of dactylitis in psoriatic arthritis. Dactylitis is a key feature of this disease, a poor prognostic marker and a target for treatment. Almost all new drugs tested in psoriatic arthritis are tested using this metric

The Leeds Dactylitis Index measures the severity and activity of dactylitis. It includes a measuring instrument (dactylometer) and uses an algorithm to calculate the index.

1. Healy PJ et al. (2008) MRI changes in psoriatic dactylitis--extent of pathology, relationship to tenderness and correlation with clinical indices. Rheumatology (Oxford) 47:92-95.
2. Helliwell PS et al. (2005) Development of an assessment tool for dactylitis in patients with psoriatic arthritis. J Rheumatol 32:1745-1750.