Epidemiology and Cutaneous Manifestations of Psoriasis in Saudi Arabia: A Narrative Review

Introduction

Psoriasis is a complex and multifactorial chronic inflammatory autoimmune skin disease associated with systemic manifestations. The interaction between genetic and environmental factors comprises an interplay in the pathogenesis of psoriasis.¹ It can occur at any age, although it is most common between the ages of 15 and 30.^1,2 Even though psoriasis is not contagious, the affected individuals experience significant social and psychological problems as a result of its disfiguring and debilitating effects, including loss of productivity and, worst of all, social rejection and a negative impact on their quality of life (QoL). Furthermore, psoriasis is considered a major health concern that requires a complete cure, and a well-monitored treatment can reduce its morbidity and improve quality of life.

The global prevalence is estimated to be around 2%; however, this differs from country to country.³ The prevalence of psoriasis in different nations has been observed to range from 0.09% to 11.4%.⁴ Psoriasis is prevalent in irregular intensity among different populations and ethnic groups around the world. Adult prevalence estimates range from 0.51% to 11.43%, while children’s prevalence estimates range from 0% to 1.37%.⁵ Psoriasis is considered an immune-mediated chronic illness with the involvement of crucial genetic components; however, still the identification of its causative immunogen has not been discovered.^6,7 The condition is thought to start when an unknown antigen activates T cells, causing them to secrete a variety of cytokines, which are then released by activated T cells, inflammatory cells, and keratinocytes. Thus, psoriasis can be attributed to a deficiency in keratinocyte proliferation and differentiation, as well as inflammatory cell infiltration, including T-lymphocytes, macrophages, and neutrophils.⁸ The hyper-proliferation of the keratinocyte causes the typical psoriasis lesion; therefore, psoriasis is characterized by a high rate of epidermal turnover.⁹ Psoriasis shows a genetic predisposition, but environmental variables also play a role in clinical manifestations of the disease. Therefore, ethnicity, genetics, and environmental variables all have a role in determining the disease’s prevalence. In comparison to other ethnic groups, higher prevalence rates have been found in those living in higher latitudes and white people.^6,7

In this narrative review, we provide outcome of a literature search on cutaneous manifestation, prevalence, and clinical characteristic of psoriasis with a focus on Saudi Arabia.

Literature Survey

A thorough search on cutaneous manifestations of psoriasis in the KSA was conducted from July 01, 2021 to September 30, 2021 using the key phrases “psoriasis,” “cutaneous manifestations of psoriasis in KSA,” “psoriasis clinical presentation in Saudi Arabia,” and “psoriasis skin lesions in Saudi Arabia” at four medical search stations PubMed, Scopus, Google, and Research Gate. Only English-language articles were reviewed.

Results

Psoriasis Prevalence in Saudi Arabia

The prevalence of psoriasis in the Kingdom of Saudi Arabia (KSA) varies from province to province with time, and there has been a continuous increasing trend in recent years. The highest reported to be 5.33% in Al-jouf (northern region).¹⁰ In the last decade, various studies have demonstrated the pattern of skin-related conditions in several parts of Saudi Arabia, including Asir, Riyadh, Madinah, Jeddah, Al-Khobar, Al-Baha, Qassim, Hail, Abha, Najran and Qunfudah, spanning the eastern and western province and southwestern Saudi Arabia.^11–16 However, large-scale epidemiological studies on cutaneous manifestations of psoriasis in Saudi Arabia remain rare.

In eastern and southwestern Saudi Arabia, psoriasis prevalence is estimated to be 1.5% and 3.4%.^13,14 However, a study by Al-Saeed et al demonstrated a much lower prevalence of psoriasis (0.3%) in women.¹⁵ Later, Al-Hoqail et al reported a higher prevalence of psoriasis among women (3.2%) and men (5.5%).¹⁶ Following this, Alshamrani et al reported a total of 5.1% prevalence of psoriasis among Saudis.¹⁷

Clinical Spectrum and Types of Psoriasis

The presentation of psoriasis can occur in different forms; from red scaling raised plaques on the elbows, knees, or scalp to superficial pustules dispersed on the palms or soles, or, in rare cases, wide-spread pustules all over the body. The plaque, guttate, small plaque, inverse, erythrodermic, and pustular forms of psoriasis are among the clinical spectrum’s variants (Supplementary Table). Plaque-type psoriasis is the most prominent form of psoriasis and appears as elevated red plaques with well-defined borders that are covered with silvery scales. The extensor surface of elbows and knees, the scalp, and the lower back are the most common sites of appearance, but it can also affect other parts of the body, with varying lesion sizes and symmetrical distribution.¹⁸ A variety of factors influence the clinical severity of psoriasis.¹⁹ These include variations in presentation, type of psoriasis, the extent of skin involvement, and the location of skin lesions, such as the scalp, face, nails, palmoplantar surfaces, and intertriginous regions. Psoriasis can also develop in a variety of ways, including extracutaneous symptoms.³

Types of Psoriasis Reported in Saudi Arabia

Over two decades, several studies have reported the prevalence of different types of psoriasis in different regions of Saudi Arabia (Table 1) with enormous variability in the rate of psoriasis prevalence in both males and females; adults and children. In the Hail (northern region), Psoriasis was found to be the most common papulosquamous disorder, accounting for 57.35%.²⁰ Further, age was identified as another crucial factor that has a predominant role in the clinical manifestation of psoriasis in different countries, including Saudi Arabia. Fatani et al reported the occurrence of psoriasis in King Fahd hospital, Al-Khobar (eastern region) at 5.3% of the patients following up dermatology clinic whereby 53% of individuals develop the disease before they reached the age of 30 years, in which 8.4% of the them had a family history of psoriasis.²¹ This study also showed the involvement of lower extremities (44.9%), scalp (41.8%), nail (26.6%), and palmoplantar (12.6%) as the major involved sites in the body. The most frequent reported clinical form was plaque psoriasis (87.1%), followed by erythrodermic psoriasis (4.2%), pustular psoriasis (3%), guttate psoriasis (1.9%), flexural psoriasis (2.3%), and follicular psoriasis (0.4%). In 43% of cases, itching was identified as the most common symptom mentioned by patients. Later, Bhutto et al reported different types of childhood psoriasis. Among 36 children, 33% had generalized plaque type of psoriasis while 22.2% had guttate psoriasis and 11.1% had mixed type of psoriasis. Family history was positive in 27.8%.²²

Table 1 Different Studies Showing Cutaneous Manifestations and Prevalence of Psoriasis Among Saudi Population

Al-Saeed et al conducted a cross-sectional study in Al-Khobar (eastern region), on 2239 female school children randomly selected from 30 regular public and private primary and preparatory schools.¹⁵ They reported that the frequency of skin problems among female school children in Al-Khobar city was particularly high (98.6%), and it was advised that a preventive health education programme on skin diseases be implemented for school children at various levels, as well as their families and teachers. Alhumidi et al reported the average age of onset of a patient with psoriasis is 31 years and that 69% of patients have plaque psoriasis in the KSA.²³ Shajeri et al investigated the characteristics of psoriasis in children aged one to 10 years in the southern area of Saudi Arabia (Asir and Najran regions) and reported the guttate form of psoriasis as the most prevalent (64.0%), followed by plaque psoriasis (52%) and inverse psoriasis (4%).²⁴ Similarly, Hassan et al reported plaque psoriasis as the most prevalent (24%) form of psoriasis in a tertiary hospital in Riyadh (central region).²⁵

A recent systematic review and meta-analysis demonstrated the pattern of skin disorders in a total of 30,436 patients of different geographical locations of Saudi Arabia (Almohideb, 2020) and reported skin appendages (24.8%) and dermatitis (24.0%) as the most often reported skin disorders in Saudi Arabia.²⁶ Skin infection accounted for 18.5%, whereas papulosquamous disorders accounted for 5.3%. Psoriasis accounted for 3.9%, whereas lichen planus accounted for 1.8%. Another, most recent cross-sectional study by Alajmi et al from Jeddah (western region) reported 33.6% unidentified psoriasis.²⁷ The majority of patients, however, were diagnosed with plaque psoriasis (57.0%), followed by those with psoriatic arthritis (13.3%). There were only a few cases of nail psoriasis (0.8%), pustular psoriasis (1.6%), and inverse psoriasis (1.6%).²⁷

Various local studies have also reported the prevalence of other types of psoriasis involving different sites among Saudis. (Table 2) These studies warrant further investigation for controlling psoriasis and psoriasis-related cutaneous manifestations in Saudi Arabia.

Table 2 Type of Psoriasis Prevalent and Common Sites Involved in KSA

Key Findings

The above-mentioned studies revealed that psoriasis is relatively common in Saudi Arabia, with a prevalence of up to 5.33%, and has risen somewhat over time. Male patients were more susceptible and predominant in the majority of studies in the kingdom. The age of psoriasis emergence in male patients was less than 30 years, whereas the illness appears later in female patients. Some studies suggest individuals with psoriasis had a familial history of the disease and that psoriasis prevalence was linked to genetic susceptibility. This study examined the cutaneous manifestations of psoriasis in Saudi Arabia in depth. The plaque form of psoriasis was shown to be the most frequent type of skin manifestation. Guttate psoriasis was the second most common kind of psoriasis. Other types of psoriasis, such as pustular psoriasis, erythrodermic psoriasis, follicular psoriasis, inverse psoriasis, congenital, and mixed psoriasis were also found in the KSA. The lower limbs were the most common location of psoriasis presentation among Saudi patients. The scalp was the second most common location, followed by the palmoplantar, elbow, and genitalia.

Discussion

Psoriasis is a critical public health problem since it has a significant impact on QoL and has financial ramifications. Even though psoriasis is not contagious, patients may face significant social stigmatization and psychological problems as a result of its disfiguring and debilitating effects, including loss of productivity and, worst of all, social rejection. Furthermore, psoriasis is considered a significant health condition that requires care because of related comorbidities, particularly cardiovascular complications.⁴² It is underdiagnosed and undertreated throughout the world. Many nations, including the KSA lack a high-quality health registry on psoriasis.

Large epidemiological research on cutaneous manifestations of psoriasis is infrequent in Saudi Arabia. Several studies have looked into the pattern of skin disorders in different parts of the kingdom. This review reveals that psoriasis is fairly common in Saudi Arabia, with a frequency range from 1.51% in Najran (southern region) as high as 5.33% in Al-jouf (northern region).^10,13 This variation may be related to different methodological studies and heterogeneity of the data presented. These data also are higher than estimated reports by many countries.⁴² Thus, they need to be interpreted with caution. In addition, the prevalence of psoriasis has risen somewhat over time in keeping with international studies.^43–45 This increase may be attributed to the interaction between the genetic and environmental factors as well as the availability of health care systems to provide psoriasis care.⁴⁵ Further studies are needed to establish the proper rationale for the rise in psoriasis prevalence in Saudi Arabia. Male patients are more sensitive to psoriasis according to the current study, and there is a male predominance in both the frequency and severity of psoriasis among Saudis. However, there was no agreement about whether the prevalence of psoriasis differed between men and women worldwide.⁴² In this study, plaque psoriasis is the most frequent form in the major regions of Saudi Arabia with a prevalent rate reaching 87% except in the southern regions where guttate psoriasis is more predominant.^23,24 Guttate psoriasis is the second most common form of psoriasis in the majority of Saudi research (Table 2). The prevalence of guttate psoriasis vary widely in our study and others who cite the prevalence of less than 30% among patients with psoriasis.⁴⁵ Our findings are consistent with other studies that have quoted a high incidence of plaque psoriasis.^44,45

Other phenotypes of psoriasis are infrequently reported. Inverse psoriasis and pustular psoriasis were found to be rare in the current research, accounting for only 5% of patients with psoriasis. Congenital psoriasis and follicular psoriasis were revealed to be the least frequent forms of psoriasis among the Saudi population in this study. These findings are in line with international literatures.^1,7 Finally, the reviewed data showed that Psoriasis is unequally distributed in the KSA and there is still limited information about the epidemiology of the disease. Therefore, further studies that include a comprehensive screening for the type of psoriasis and a reliable stratification of clinical presentation and possibly genetic study will provide robust information that can aid in the development of specialized health initiatives and treatment regimens.

Conclusion

Psoriasis is quite common in Saudi Arabia and it was more prevalent in the northern region. Plaque-type psoriasis is the most frequent cutaneous manifestation, followed by guttate type. The data’s heterogeneity makes comparison difficult. Therefore, the consistency in reporting the clinical manifestation of psoriasis and possibly establishing a regional registry for the disease is highly sought after. It is also critical to have a better understanding of the epidemiology of psoriasis so that resources may be targeted to enhance the disease’s prevention and minimize its, morbidity, disability, and death.

Strength and Limitation of the Study

The comprehensive search of all available literature on cutaneous symptoms of psoriasis from KSA is one of this review’s strengths. The research’s variability in terms of age, gender, region, and environmental triggers make the comparison difficult. Furthermore, the data of some studies were collected retrospectively which makes the conclusion up for debate.