2. Dermatology Life Quality Index (DLQI) questionnaire.

Number	Question	Answer options
1	Over the last week, how itchy, sore, painful, or stinging has your skin been?	Very much A lot A little Not at all
2	Over the last week, how embarrassed or self‐conscious have you been because of your skin?	Very much A lot A little Not at all
3	Over the last week, how much has your skin interfered with you going shopping or looking after your home or garden?	Very much A lot A little Not at all Not relevant
4	Over the last week, how much has your skin influenced the clothes you wear?	Very much A lot A little Not at all Not relevant
5	Over the last week, how much has your skin affected any social or leisure activities?	Very much A lot A little Not at all Not relevant
6	Over the last week, how much has your skin made it difficult for you to do any sport?	Very much A lot A little Not at all Not relevant
7	Over the last week, has your skin prevented you from working or studying? (If "No", over the last week, how much has your skin been a problem at work or studying?)	Yes No Not relevant
8	Over the last week, how much has your skin created problems with your partner or any of your close friends?	Very much A lot A little Not at all Not relevant
9	Over the last week, how much has your skin caused any sexual difficulties?	Very much A lot A little Not at all Not relevant
10	Over the last week, how much of a problem has the treatment for your skin been, for example, by making your home messy or by taking up time?	Very much A lot A little Not at all Not relevant

The aim of the Dermatology Life Quality Index (DLQI) questionnaire is to measure how much the life of adults has been affected by their skin problem over the last week. The DLQI is calculated by summing the score of each question, resulting in a maximum of 30 and a minimum of zero. The higher the score, the more quality of life is impaired. The scoring of each question is as follows: Very much (three), A lot (two), A little (one), Not at all (zero), Not relevant (zero); question seven = Yes (three) to unanswered (zero).

Meaning of the total DLQI score: zero to one = no effect at all on patient's life; two to five = small effect on patient's life; six to 10 = moderate effect on patient's life; 11 to 20 = very large effect on patient's life; 21 to 30 = extremely large effect on patient's life. Minimal Clinically Important Difference (MCID) of the DLQI: a change in DLQI score of at least four points is considered clinically important (Basra 2008).

Finlay 1994 developed the DLQI. The following website provides further information and interpretation: www.dermatology.org.uk.