Macular amyloidosis (MA) is the most common type of primary localized cutaneous amyloidosis (PLCA).1 It typically presents in the upper back or the extremities forming pruritic regions with undefined borders.1 The treatment options for PLCA are diverse but still not definitive.2 Since somatic symptom relief is not an immediately achievable end, it is important to consider the psychological comorbidities of PLCA.

MA is often associated with pruritus, which can potentially limit patients’ functioning, comparable to chronic pain.3 Furthermore, MA lesions are esthetically displeasing and may cause stigmatization, particularly considering the higher prevalence in women.4 Therefore, it is important to consider MA's impact on psychosocial performance and quality of life (QoL), even though the disease is not clinically severe. So far, only one study has investigated this matter, reporting social and emotional role limitations and mental health decline.5 This study was aimed to investigate QoL and the extent of psychopathologies in Iranian patients with MA. The results of this study can be of particular interest, since Iran's unique culture and dress code makes skin lesions normally covered in public.

In total, 40 female participants (20 in each study group) with an average age of 36.80±10.19 years (ranging 13–53 years) were included. Based on t-test and Chi-square test, the case and control groups were not significantly different in age (P=0.668), marital status, education, employment, or family history of similar disease. The average disease duration was 5.05±3.30 years (ranging 1–12). Regarding lesion location in the case group (n=20), eight (40%) were covered (back or torso), four (20%) were uncovered (head, neck, or upper limbs), and eight (40%) were both. The mean pruritus severity was 5.30±3.46: score-0 (n=3, 15%); score-1 (n=2, 10%); score-2 (n=1, 5%); score-6 (n=4, 20%); score-7 (n=7, 35%); score-8 (n=2, 10%); score-10 (n=1, 5%).

According to Table 1, the SF-36 score was significantly greater in the control group; total (P<0.001) and in three subscales: role limitation due to emotional health (P<0.001), social functioning (P<0.001), and emotional well-being (P=0.002). Regarding the SCL-90-R scores, the case group had greater total scores, as well as, the ‘depression’, ‘obsessive-compulsive’ and ‘interpersonal sensitivity’ dimensional scores (P<0.001). Furthermore, GSI, PSDI and PST were significantly higher in the case group (P<0.001).

The case group answered the DLQI survey (Supplementary Table 1) resulting in a mean score of 10.95±3.60 (ranging 3–19). Accordingly, the effect on QoL in this group (n=20) was very large in ten (50.0%), moderate in nine (45.0%), and small in one (5.0%) case. Table 2 demonstrates the results of linear regression models, indicating that age can significantly predict DLQI score. Furthermore, after being adjusted, pruritus severity, location of lesions and marital status could significantly predict DLQI as much as 78%. Linear regression found no significant relationship between the SCL-90-R and SF-36 scores and the demographic or symptomatic features.

Age was positively correlated with DLQI score (P=0.048; r=0.447), and the pain subscale of SF-36 was correlated with pruritus severity (P=0.018; r=0.521) and the DLQI score (P=0.044; r=0.455). In addition to these, pruritus severity was correlated negatively with paranoid ideation (P=0.027; r=0.521) and positively with DLQI score (P<0.001; r=0.776).

According to one-way analysis of variance, the DLQI score was not different between the married and single groups (P=0.236), while it was significantly different (P=0.001) between the three lesion location groups (covered; uncovered; and both). Tukey's test showed that patients with covered lesions had a higher QoL, compared with the other two groups (P<0.05).

Controlling somatic symptoms and accompanying psychological comorbidities has been acknowledged as an important element of disease management in recent years. Here, we used multiple questionnaires to investigate the impact of MA on mental health and QoL. Similar to our findings, Fang et al. discovered low SF-36 scores in the dimensions of emotional well-being, social functioning, and role limitation due to emotional health, among PLCA patients.5 The mean DLQI score in our study was higher than what Fang et al. reported (9.05±3.88); however, this is not surprising since we only investigated one subtype of PLCA and our sample size was limited in comparison.

DLQI score among PLCA patients has been reported in few studies. A study recorded the preliminary DLQI among MA and lichen simplex patients as a secondary outcome reporting a mean score of 8.25±10.5.10 A study on DLQI among females with acquired skin pigmentations showed that 40% of MA patients were very largely affected while 33.3% were moderately affected.11 We found that the mean DLQI score among MA patients was 10.95±3.60, while studies in similar populations indicate that this score in psoriasis, vitiligo, acne and burn injury is 6.46,12 7.05,6 6.4213 and 17.7,14 respectively. These demonstrate that MA is comparatively more impactful on QoL; however, it is worth noting that based on DLQI scores, most patients in our study (>90%) were experiencing very large to moderate effects. Furthermore, our findings of the DLQI score indicated a greater impairment of QoL in patients with uncovered lesions, which is in line with previous reports.15

No study had previously investigated the SCL-90-R in MA patients; however, compared with a healthy population, the total SCL-90-R is reportedly greater in patients affected by chronic pruritic skin lesions, with more prominent difference in the ‘obsessive-compulsive’ and the ‘depression’ dimensions.16 MA is a condition often accompanied by chronic pruritus, and as such, our findings are in line with studies on pruritic conditions.4,17 Pruritus is comparable to chronic pain3 and it can lead to sleep disorders, which can lead to depressive and anxious symptoms, ultimately reducing QoL.18

Even though, we found that older patients experience a greater impact on their QoL, studies with more diverse populations have concluded that younger age is associated with a greater impact on QoL among patients with PLCA and other skin conditions.5,19 Younger people, particularly women, appear to be more self-conscious about their physical image compared with older people, and they can have a harder time dealing with their condition, signifying the importance of a simultaneous psychiatric and symptomatic approach.

This study was the first in this region to evaluate the mental health implications of PLCA, although some limitations were present. We employed convenience sampling and did not incorporate treatment progress and stage of disease as variables into our analysis. Furthermore, due to our limited sample size, it was not feasible to adequately examine the variables predicating the impact of QoL on MA using logistic regression. Nonetheless, our study indicated that MA patients have an impaired QoL, which can be influenced by factors such as age, severity of pruritus, and the location of skin lesions (covered or uncovered). Our findings may signify the value of a multidisciplinary approach to patients with MA.

This work was financially supported by Mashhad University of Medical Sciences [grant number 970178].

The authors declare they have no conflict of interest.