Background: Alternative criteria for initiating antiretroviral therapy to CD4 testing or clinical illness are needed in Malawi.
Method: We tested if grey nails could be used to identify patients with a CD4 cell count less than 200 cells/microl who had not yet presented with AIDS-defining illnesses.
Results: Using a set of 242 photographs we showed good inter-observer agreement for grey nails (kappa = 0.66; P < 0.0001) and the positive predictive value of grey nails for a CD4 cell count of less than 200 cells/microl was 81% (chi < 0.0001).
Conclusions: Grey nails have been associated with HIV infection and we have shown significant correlation of this sign with a low CD4 cell count. For clinicians working in sub-Saharan Africa without access to CD4 cell count testing, grey or DB nails represent an additional staging sign to help identify a sub-group of patients likely to benefit from ART.