The importance of a full clinical examination: assessment of index lesions referred to a skin cancer clinic without a total body skin examination would miss one in three melanomas.

Traditional clinical teaching emphasises the importance of a full clinical examination. In the clinical assessment of lesions that may be skin cancer, full examination allows detection of incidental lesions, as well as helping in the characterisation of the index lesion. Despite this, a total body skin examination is not always performed. Based on two prospective studies of over 1,800 sequential patients in two UK centres we show that over one third of melanomas detected in secondary care are found as incidental lesions, in patients referred for assessment of other potential skin cancers. The majority of these melanomas occurred in patients whose index lesion turned out to be benign. Alternative models of care--for instance some models of teledermatology in which a total body skin examination is not performed by a competent practitioner--cannot be considered equivalent to a traditional consultation and, if adopted uncritically, without system change, will likely lead to melanomas being missed.

Are subjective accounts of itch to be relied on? The lack of relation between visual analogue itch scores and actigraphic measures of scratch.

There is a widespread belief that subjective accounts of disease are key components of measures of disease severity and quality of life. In the present study we have set out to test this hypothesis using visual analogue scales (VAS) for itch, as a subjective measure, and actigraphy as an objective measure. One-hundred and seventeen itchy children and adults (and 25 controls) were studied for clusters of nights (total number 1,654) and actigraphy scores and VAS itch taken daily. Fifty-six percent of the night-to-night variation in actigraphy scores occurred between different individuals, while 44% was intra-subject. Neither age nor sex (children's or adults') predicted actigraphy scores, and the only significant predictor of actigraphy score was disease type (p = 0.001, r² = 0.51). In a multivariate model VAS itch score was not a significant determinant of actigraphy scores for either children or adults (p = 0.26). In order to see if there was a relation between VAS itch and actigraphy within the same patients (rather than between patients), 20 eczema patients wore the actigraph and scored VAS itch nightly for 42 nights. Little relationship was found between the actigraphy score and the VAS itch. Empirical autocorrelation analysis of VAS itch and actigraphy score reveal a clear autocorrelation for subjective VAS scores that was not found for the objective actigraphy score. Our data suggest a dissociation between scratch and perceived or recalled itch. One explanation is that VAS itch scores suffer from considerable anchoring, and context bias, and that their use in measures of disease severity is problematic.

How robust are the Dermatology Life Quality Index and other self-reported subjective symptom scores when exposed to a range of experimental biases?

Subjective-symptom tools used in dermatology have rarely been experimentally tested for cognitive "focus" and "framing" biases. We investigated the effects of affective biases on the Dermatology Life Quality Index (DLQI), the Global Health Question and visual analogue scores. Two experiments tested the response to affect-eliciting words and film. We demonstrated no significant difference in median DLQI scores for subjects exposed to negative vs. neutral words (medians 8.5 and 9.5, respectively), or negative vs. positive words (medians 6.0 and 9.0, respectively, overall p = 0.41.) Median DLQI scores were similar for groups who had (8.0), or had not (9.0), seen a video clip about a severe skin condition (p = 0.34). Finally, we compared an Amended DLQI (ADLQI), the DLQI re-worded into neutral "frames", with the standard DLQI. ADLQI median scores were higher (ADLQI 8.25, DLQI 6.75), but not significantly so (p = 0.47). We have been unable to demonstrate any effects of the biases studied, but the statistical power of our study is modest.