The estimation of the body surface area (BSA) involved in psoriasis may be reliably performed by patients using the Self-Assessment Cutaneous Inflammatory Disease Extent Score (SA-CIDES) with more accurate results than the rule of hands, according to a research letter published in the British Journal of Dermatology.

The current standard methods of patient self-assessment in the estimation of the BSA affected by their psoriasis or eczema are the rule of hands and the rule of nines, although these methods have not been extensively validated. The cutaneous inflammatory disease extent score method of estimation has been validated for use by physicians, but the self-assessment version has not yet been validated.

To determine if the SA-CIDES could accurately be used in the estimation of involved BSA for patients with psoriasis and eczema, data from 39 patients (49% women) was analyzed. The median age of patients was 51 years (interquartile range, 39.5-67.0). All patients were asked to fill out the SA-CIDES, which was an unmodified template of the CIDES. The estimates from the SA-CIDES and the rule of hands were compared with a blinded assessment of the patients’ photographs by 3 medically trained observers.

Intraclass correlation coefficients (ICCs) were “excellent” for SA-CIDES and “good” for the rule of hands (ICC patients-experts 0.93 vs ICC patients-nonexperts 0.94 and ICC patients-experts 0.80 vs ICC patients-nonexperts 0.85). The difference in self-assessment and expert estimation increased with higher involved BSA, but the increase in difference was smaller for SA-CIDES than the rule of hands. The rule of hands also resulted in an overestimation of involved BSA by patients compared with medically trained observers’ estimates.

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The results of this study showed that SA-CIDES is a more accurate self-assessment method for the involved BSA of psoriasis and eczema than the rule of hands, the researchers believe. As this was a pilot study, larger studies with a larger number of expert raters are warranted.


Speechaert R, Lambert J, Delbaere L, Lesseliers T, vanGeel N. The reliability of the Self-Assessment Cutaneous Inflammatory Disease Extent Score (SA-CIDES) and the rule of hands to assess the involved body surface area in psoriasis and eczema. Published online July 30, 2020. Br J Dermatol. doi: 10.1111/bjd.19430