Accurately diagnosing the subtype of Epidermolysis Bullosa (EB) is critical for management and genetic counseling. Modern laboratory techniques are largely inaccessible in developing countries, where the diagnosis remains clinical and often inaccurate. We developed a matrix indicating presence or absence of a set of distinctive clinical features (rows) for the 9 more prevalent EB subtypes (columns). To test an individual patient, the presence or absence of these features was compared to the findings expected in each of the 9 subtypes to see which corresponded the best. If two or more diagnoses scored equally, that with more specific features was selected. The matrix was tested using findings from 74 genetically characterized patients with EB aged >6 months by an investigator blinded to molecular diagnosis. Matrix diagnoses were compared with molecular diagnoses for concordance.Overall, the concordance between the matrix and molecular diagnosis for the 4 major types of EB was 91.9% (kappa co-efficient: 0.88±0.07; p<0.001). The matrix achieved a 75.7% agreement (kappa co-efficient: 0.73±0.04; p<0.001) in classifying EB into its 9 sub-types. The matrix appears to be simple, valid and useful in predicting the type and subtype of EB. An electronic version will facilitate further testing.

Yenamandra, V.K., Moss, C., Sreenivas, V., Khan, M., Sivasubbu, S., Sharma, V.K. and Sethuraman, G.
Development of a Clinical Diagnostic Matrix for characterising Inherited Epidermolysis Bullosa.