Thyroid function in hidradenitis suppurativa: a population-based cross-sectional study from Denmark.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic inflammatory disease. Numerous studies have associated HS with obesity, and recently with metabolic syndrome (MetS). Both obesity and MetS are linked with metabolic changes. Thyroid hormones play a central role in metabolism and exert pleiotropic effects on adipogenesis and the basal metabolism of lipids and glucose. We hypothesized that patients with HS have an altered or dysfunctional metabolism expressed as thyroid function. AIM: To investigate thyroid function in individuals with HS compared with healthy controls (HCs). METHODS: We conducted a retrospective comparative cross-sectional study using blood samples and questionnaire-based self-reported information to assess thyroid function. RESULTS: Our study comprised 430 patients in a population-based HS group, and 20 780 HCs. The age/sex-adjusted analysis showed a significantly lower level (P < 0.001) of thyroid-stimulating hormone (TSH) and a significantly higher level (P < 0.0001) of total triiodothyronine (tT3) for the HS compared with the HC group. The age/sex-adjusted analysis also showed a significant association between clinical hyperthyroidism and HS (an OR = 1.91, 95% CI 1.19-3.07; P = 0.02). When this analysis was adjusted further for the potential confounders of body mass index, smoking and oral contraception, the results remained significant. CONCLUSION: This study suggests that HS is associated with hyperthyroidism. Hyperthyroidism may indicate an altered or dysfunctional metabolism.

Spanish version of the Actinic Keratosis Quality of Life questionnaire.

BACKGROUND: Patient-reported outcome measures are very important outcomes. For specific diseases, health-related quality of life-instruments (HRQoL) are increasingly used to provide data on patients' overall perceptions of the course of a given disease. Actinic keratoses (AKs) are common keratotic lesions that occur on chronically sunlight-exposed skin. Only few studies regarding HRQoL in AKs have been made. OBJECTIVE: In order to be able to compare HRQoL among different countries and cultures, we aimed to translate and validate the Actinic Keratosis Quality of Life (AKQoL) questionnaire into Spanish and quantify the impairment caused by AKs in Spanish patients. METHODS: The AKQoL was translated. Then, 15 patients with AKs were interviewed to ensure cultural adaption before it was tested in one hundred patients with AK lesions at the Melanoma Unit of Hospital Clinic in Barcelona. RESULTS: Validation showed high interitem correlations, as well as a high correlation of each item and the total score. Internal consistency (Cronbach's coefficient alpha) was also high at 0.91 and an alpha value of 0.90 at retest. The test-retest correlation was 0.96, and the intraclass coefficient was 0.98. CONCLUSION: The presented data support the AKQoL Spanish version as a valid and reliable HRQoL questionnaire for the description of AK-related QoL and may provide a method for comparison of AK specific QoL between different cultures and countries.

Cancer incidence among patients with a hospital diagnosis of pruritus: a nationwide Danish cohort study.

BACKGROUND: Pruritus is a frequent complaint in patients with cancer. However, no large study has examined pruritus as a marker of undiagnosed cancer. OBJECTIVES: To examine the association between inpatient, outpatient and emergency hospital diagnoses of pruritus and subsequent cancer diagnoses. METHODS: In this nationwide Danish cohort study, we used medical databases to identify all patients (n = 12,813) with a diagnosis of pruritus during the period 1978-2011 and followed them until a first-time cancer diagnosis, emigration, death or 31 December 2011. We computed standardized incidence ratios (SIRs) for cancer as the observed to expected number of cancers based on national cancer incidence rates. We calculated the 1-year absolute risk of cancer, treating death as a competing risk. RESULTS: The overall SIR of cancer was 1.13 [95% confidence interval (CI) 1.07-1.20]: 1.22 (95% CI 1.13-1.33) among men and 1.05 (95% CI 0.97-1.14) among women. The SIR was 1.20 (95% CI 1.08-1.33) among patients with a previous diagnosis of dermatological disease and 1.10 (95% CI 1.02-1.18) among patients without such a diagnosis. Both haematological and various solid cancers were observed at increased rates. Overall, the highest SIRs were observed during the first 3 months of follow-up, declining rapidly thereafter. The 1-year absolute risk of a cancer diagnosis was 1.63% and 155 patients with pruritus would have needed to be examined to detect one excess cancer. CONCLUSIONS: Pruritus may be a marker of occult cancer. Further studies are needed to assess the prognostic benefit of screening for cancer in patients with pruritus.

Assessing the influence of actinic keratosis on patients' quality of life: the AKQoL questionnaire.

BACKGROUND: Limited knowledge is available regarding quality of life in patients with actinic keratosis (AK). OBJECTIVES: To develop and validate a disease-specific questionnaire - the Actinic Keratosis Quality of Life questionnaire (AKQoL) - to assess the quality of life of patients with AK. METHODS: Based on an extensive literature search and patient interviews, the AKQoL was developed in a stepwise approach. An initial mega-questionnaire was composed and subsequently shortened based on statistical differences between patients and controls. A test-retest was done to establish the reliability and to refine the items further. Rasch analyses were performed on the final questionnaire. RESULTS: Initially, 175 items were tested in a mega-questionnaire. The questionnaires were sent out twice and statistical analyses were made, reducing the number of questions to 18 and 10, respectively. Subsequent inter-item correlations showed that one item had only a weak correlation to the rest of the scale. This was confirmed by the Rasch model and by internal consistency as evaluated by Cronbach's coefficient alpha. Only one item was found to provide a small sex difference. A Bland-Altman plot showed excellent reliability. Items are scored on a standard 4-point Likert scale and summarized in a total score of maximum 27 points. A higher score indicates greater quality of life impairment. CONCLUSIONS: A nine-item questionnaire for patients with AK was developed. The AKQoL has three domains covering emotions, function and control and one single global item. The questionnaire's scale structure, the content and face validity, and the reliability have been established.