A number of clinician rated scar scales are commonly employed within clinical practice, but many of them fail to accurately capture the patient centred, QoL impact of keloid scars. By definition all scar assessment scales are highly subjective, typically consisting of arbitrary parameters judged on visual approximation by an observer. With the exception of POSAS which includes the single weighted criteria of “itchiness” none of the established scar scales take into account patient reported symptoms (Vancouver Scar Scale (VSS), Manchester Scar Scale (MSS) and Visual Analogue Scale (VAS)).
It is therefore essential for clinicians to have scales available that are designed to accurately simulate patients’ perceptions of their scars as experienced by them. In order to do this any keloid scar scale must measure clinical outcomes of treatment not only on aesthetic criteria, but also on an appropriately weighted background of the accompanying physical and psychological symptoms. In addition to this any candidate questionnaire must prove to be reliable, easy to conduct in the clinical environment and sufficiently sensitive to detect changes in outcomes pre and post treatment.
Previous studies on keloid scar patients have noted that “pruritis” and “pain” are the two common reported physical symptoms that affect patients QoL8. This study is the first to objectively measure in qualitative and quantitative terms the pain experienced by keloid scar patients. Results from the MSF-PQ showed that the four most common pain descriptors used to describe keloid scars were all sensory (throbbing, sharp, aching and tender).This is consistent with the fact that keloid scars are local discreet lesions that rarely have an affective component to the pain.
The overall QoL impact scores (DLQI) were more strongly correlated with the psychological symptoms scores (DAS-24, r=0.54, Figure 4 ), than the physical symptom scores (MSF-PQ, r=0.43). One previous study has shown similar results demonstrating that the greatest effect on patients QoL is due to the psychological distress of living with a chronic disfiguring skin condition [13
]. Mean DAS-24 scores of Keloid scar patients were shown to be greater than in the average population and consistent with other groups of patients with disfiguring skin conditions (burns) [15
]. This was best demonstrated in patients with “moderate-very large” QoL impact scores; they demonstrated high levels of avoidance behaviours that were captured well in both the DAS-24 and DLQI total scores. Overall mean DLQI scores of the patients indicated that keloid scars had a “moderate” QoL impact but that the range was large, 0-24 (“no – very large” QoL impact) [16
The Dermatology Life Quality Index (DLQI) is a clinical measure that has been validated for use in a number of other chronic skin conditions including, psoriasis [18
], vitiligo [19
], severe acne [20
] and Keloid disease [21
]. Previous studies have shown the DLQI to have good content validity [20
] and to be a sensitive enough tool to detect meaningful changes in the QoL impact scores over time in response to treatment (Psoriasis) [22
]. This study was able to show that the DLQI had an excellent internal consistency for keloid scar patients ( α =0.86) and that all 6 sections of the questionnaire were consistent with one another (item-total correlation, Figure 4). In addition our results showed that the DLQI was a sensitive screening tool for detecting overall scar pain (MSF-PQ), it helped to differentiate well between those who had severe and non-severe physical symptoms in an abbreviated single pain question.
The presence of scars hidden beneath the cloth line was shown to paradoxically increase patients QoL impact scores. A previous study conducted on raised (keloid and non keloid) scars showed similar results suggesting that the presence of visible scars allows patients to better habituate to their presence and the associated psychological stigma [23
]. Further analysis of the QoL scores showed that patients with hidden scars report higher mean scores (p<0.05) in (4/6) of the DLQI components: (symptoms/feelings, leisure, personal relationships and treatment). These results show that patients with hidden keloid scars were associated with a greater psychosocial burden and that patients adopt a range of concealment strategies to cope.
The results of this study have shown that QoL life assessment (DLQI) in Keloid scar patients can be of two major benefits. Firstly it can be used as a patient centred measure of clinical outcome to be used in parallel with other established objective scar scales. Both patient subjective and clinician objective measure can be used together to better define clinical outcomes and measure the true impact of any KD treatment.
Secondly the convergent validity of the DLQI with validated psychometric measures (DAS-24) enables it to be used as a psychological screening tool. Those patients with high QoL impact scores can be recommended for comprehensive psychological assessment and intervention if needed to compliment medical treatment. The DLQI is compact (10 questions) and easy to administer, its proven validity and clinical value support its use in routine Keloid scar treatment assessment.