|Year : 2022 | Volume
| Issue : 2 | Page : 155-160
Psoriasis in Kaduna, North-West Nigeria: A twenty-year experience
Department of Internal Medicine, Barau Dikko Teaching Hospital, Kaduna State University, Kaduna, Nigeria
|Date of Submission||19-Jan-2022|
|Date of Decision||06-Feb-2022|
|Date of Acceptance||16-Feb-2022|
|Date of Web Publication||23-Apr-2022|
Department of Internal Medicine, Barau Dikko Teaching Hospital, PO Box 9727, Kaduna
Source of Support: None, Conflict of Interest: None
Background: Psoriasis is a chronic inflammatory skin disease which may be associated with joint, cardiovascular, metabolic or psychiatric disease. Countries in North America, Northern Europe and Australia have the highest burden of disease while those in Asia, South America and Africa, the lowest. We report our experience of psoriasis in Kaduna, Nigeria, over 20 years and compare this with previous reports in the same area and in other parts of Nigeria and Africa. Objective: To report the relative incidence, clinical presentation, severity and associations of psoriasis seen over 20 years. Methods: A retrospective review of records of patients with psoriasis seen at two outpatient dermatology clinics in Kaduna, North-West Nigeria, over 20 years. Results: Diagnosis of psoriasis was made in 218 of 39,037 (0.6%) patients with new skin disease: Mean age 35.2 years, range (6 months to 80 years), 60% <40 years, males constituted 64.2%. Mean age of onset was 30.5 years with a quarter developing psoriasis before age 20 and 71.4% before 40 years. Psoriasis presented earlier in females than males (mean age of onset 27.6 vs. 32.2 years, P= 0.052) but was less severe. Psoriasis types were: Plaque 88.1%, guttate 6%, erythrodermic 4.6% and sebopsoriasis 0.9%. Only four patients had joint disease and other associations were infrequent. Overall, 80.3% had mild psoriasis and 13.2% had a family history. Conclusion: Psoriasis remains a rare and mild disease in Kaduna and is infrequently associated with joint and other systemic disease but similar in other respects to the condition elsewhere.
Keywords: Epidemiology, Kaduna-Nigeria, psoriasis, relative incidence, sub-Saharan Africa
|How to cite this article:|
Yahya H. Psoriasis in Kaduna, North-West Nigeria: A twenty-year experience. Niger Postgrad Med J 2022;29:155-60
| Introduction|| |
Psoriasis is a chronic autoimmune inflammatory skin disease which typically presents as well-defined, single to confluent plaques with uniform thick silvery or grey scales on the trunk, upper and lower limbs and scalp. Histologically, it is characterised by parakeratosis, hypogranulosis, regular acanthosis with elongation and clubbing of rete ridges, suprapapillary thinning, dilated dermal capillaries, an inflammatory infiltrate of T-lymphocytes in the dermis and epidermis. Munro's microabscesses in the stratum corneum, and pustules of Kogoj in stratum spinosum, when present, are pathognomonic of psoriasis. It is now recognised that the disease can be associated with other non-cutaneous disorders such as joint disease, cardiovascular and metabolic abnormalities which may contribute to the morbidity and disability caused by the disease. Although mortality directly related to the skin disease is low, as a result of its chronicity and recurrent nature, psoriasis can have a profound influence on the quality of life of patients and can be associated with psychiatric abnormalities such as anxiety, depression, substance abuse and social isolation; the reduction in physical and mental functioning caused by psoriasis has been found to be similar to that seen in arthritis, hypertension, heart disease, diabetes and depression. The direct, indirect and other costs related to psoriasis or its associated diseases can be substantial and were estimated to be 112 billion dollars in the United States in 2013, where psoriasis affects up to 7.2 million adults., In 2014, it has been estimated that up to 100 million people live with psoriasis worldwide and member states of the World Health Organisation, through the World Health Assembly, recognised psoriasis as a serious noncommunicable disease, which affects both children and adults, and impacts people's lives leading to needless suffering.
Parisi et al., on behalf of the Global Psoriasis Atlas, in a systematic review of the population incidence and prevalence of psoriasis, found a great geographical variation in the incidence and prevalence of psoriasis. Incidence of the disease was as low as 30.3/100,000 person-years in Taiwan to as high as 321/100,000 person-years in Italy. The prevalence of psoriasis ranged from 0.14% in East Asia to 2% in Australasia. Although population-based studies have not been carried out in much of Africa to determine the incidence and prevalence of the disease, the proportion of patients with psoriasis among those attending dermatology clinics gives an idea about the relative incidence of the disease. Various reports from all over sub-Saharan Africa have indicated that psoriasis is not as common as in other parts of the world and also there is clear variation in the rates of psoriasis reported from skin clinics with rates as low as 0.025% in Mali, West Africa, to as high as in 4%% in South Africa. In Nigeria, rates also vary. Nnoruka reported 0.4% of her patients attending an outpatient dermatology clinic in Enugu in Southeast Nigeria were diagnosed with psoriasis while Ayanlowo and Akinkugbe found that up to 1.1% of the patients attending a similar clinic in Lagos, Southwest Nigeria had psoriasis.
In two previous reports about psoriasis in Kaduna and Zaria (82 km to the north) in Northwest Nigeria, the only published reports from northern Nigeria, Jacyk and Obasi documented their experience with psoriasis seen between 1975 and 1984. They both diagnosed the disease in 0.8% of their patients and described the clinical characteristics and associations of the cases they saw. Our report is an update on the disease in patients seen for 20 years between 2001 and 2021. It is hoped that this will highlight any change in trend in the relative incidence and presentation of the disease over time and an increased understanding of this characteristic disease.
| Methods|| |
Study type and setting
This was a retrospective study of all consecutive patients presenting with new skin disease in the dermatology clinics of Barau Dikko Teaching Hospital and Habbat Medical Centre, in Kaduna, Nigeria from September 2001 to November 2021. Data were collected from November 2021 to December 2021. Ethical approval was granted by the Health Research Ethics Committee of Barau Dikko Teaching Hospital, Kaduna, Nigeria on 11th January 2022 with reference number BDTH/MAC/GEN/45/VOL/1. Patients' confidentiality was strictly maintained. Kaduna, located on 10.5015o N, 7.4408o E coordinates in northwest geopolitical zone of Nigeria, is a cosmopolitan city and its estimated current population is about 1.6 million. It is the capital of Kaduna State and was the former political capital of the defunct Northern Nigeria region. Patients were self-referred or referred from public and private healthcare facilities and came from within Kaduna and from outside Kaduna as far away as Sokoto, more than 400 km away, and Maiduguri, 755 km. All the patients were examined by a dermatologist.
Medical records of patients diagnosed with psoriasis, either clinically or after histological examination, where appropriate, were retrieved and demographic data, duration and type of disease as well as precipitating and associated factors, and co-morbidities extracted. The severity of psoriasis was assessed based on body surface area (BSA) affected and was classified as mild (≤10% of BSA affected) and severe (BSA >10%) in accordance with a recommendation of the International Psoriasis Council
Data were entered into IBM SPSS Version 22, Armonk, New York, USA, 2013 and descriptive statistics were obtained. Chi-squared or Fisher's Exact tests and Independent-Sample t-tests were used to assess the significances of differences in categorical and continuous variables, respectively. A P < 0.05 was considered significant.
| Results|| |
Demographics and basic information about patients
[Table 1] shows demographic and other information about the patients. Over a period of 20 years, 218 out of 39,037 (0.6%) patients with new skin disease were diagnosed with psoriasis. These patients also constituted 218/28,887 (0.8%) with a non-infectious skin disease. Just about a quarter of the patients came from within Kaduna metropolitan area, while up to 15% of patients came from more than 200 km away. 64.2% were male. The mean age of patients at presentation was 35.2 years, with the youngest being 6 months and the oldest 80 years. 15/208 (7.2%) were aged <10 years and almost 60% were below the age of 40. The mean age at onset of psoriasis was 30.5 years with peak age at onset being 20–29 years. Almost a quarter of patients developed psoriasis before age 20 while nearly three-quarters of patients (71.4%) had onset of psoriasis before the age of 40 years. The mean age of onset was lower in females than males but did not reach statistical significance (27.6 years vs. 32.2 years, t 1.956, P 0.052, confide interval [CI] of difference-0.038–9.159).
Clinical characteristics of psoriasis
Overall, patients had psoriasis for a mean of 62.4 months (95% CI 50.1–74.7) before presentation with females having psoriasis longer (68.8 months) than males (58.8 months) although this was not statistically significant (P 0.445). [Figure 1] shows different types of lesions which patients with psoriasis presented with. Almost 90% of patients presented with plaque psoriasis. Guttate psoriasis was diagnosed in 13 (6%) of patients, 62% of whom were below the age of 20 years while erythrodermic psoriasis occurred in 10 patients, four of whom also had HIV infection. Generalised or palmoplantar pustular psoriasis was not seen but a patient with plaque psoriasis developed a localised area of postulation complicating prolonged use of clobetasol propionate in an adjacent plaque [Figure 1]f. There was no difference in the type of psoriasis between males and females except erythrodermic psoriasis in which 90% were male. The trunk (chest, abdomen and back) was affected in almost all patients followed by the buttocks and the lower limbs (72%) and the upper limbs (61%). The scalp was affected in almost half of patients [Table 2] while classic areas of involvement– elbows and knees– were affected in 19.3% and 25.7%, respectively. Genital involvement– glans, coronal sulcus, shaft of penis and scrotum-was reported by 17.9% of males; no female patient reported genital involvement. The location of lesions was similar for both males and females except for the trunk in which males were affected more frequently than females [Figure 2]. Itching was reported in 80 (37.6%) of patients while Koebner's phenomenon occurred in 16/196 (8.2%) of patients. Overall, the nails were affected in one form or another in 58 (26.6%) of all patients (onycholysis 8.3%, pitting 6.9%, subungual hyperkeratosis 5.5%, onychorrhexis 5%); One patient each had oil drop change and total nail dystrophy. Joint involvement was seen in four patients only, all in small joints of hands and all associated with significant deformity [Figure 1e]; the shoulder and elbow joints were affected as well in one of the patients. In 136 patients in whom a family history was available, 18 (13.2%) had a first-, second- or third-degree relative with psoriasis. There was no significant difference in family history between those with early onset (<40 years) and those older (12% vs. 17.1%, Fisher's Exact test, P 0.575). In 80% of patients, psoriasis was classified as mild based on the involvement of ≤10% of their BSA. Although male patients had a more severe disease than females (38.3% vs. 25.6%), this did not reach statistical significance (X2 = 2.43, P 0.119).
|Figure 1: Clinical types of psoriasis: (a) Plaque– torso (b) Plaque– elbows (c) Plaque– knees (d) Plaque– scalp (e) Guttate– left thigh. Note joint involvement in small joints of lefthand (f) Pustular lesions on right upper leg. Note typical plaques on knees (g) Fingernails– onycholysis (h) HIV-associated|
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Precipitating factors for psoriasis were infrequent: There was a history of pharyngitis immediately preceding the appearance of guttate psoriasis in only two patients– one was an 8-year-old girl and the other, a 35-year-old man. In two patients, prolonged use of systemic corticosteroids precipitated erythrodermic psoriasis. Cigarette smoking, alcohol, stress, or excessive sun exposure were not a factor in any patient. Seven patients reported their skin disease became worse during the harmattan period (end of November to the middle of March).
Diseases associated with psoriasis were infrequent as well. At the time of presentation, six patients were clinically obese, three patients reported they had hypertension and two patients had chronic liver disease. HIV infection was the disease most often associated with psoriasis, seen in 15 (6.9% overall) of patients– 10 (66.7%) were below the age 40 years, 12 (80%) were male and the median duration of psoriasis was only 6 months. Nine patients with HIV (60%) presented with plaque psoriasis, 4 (26.7%) erythrodermic psoriasis and 2 (13.3%) sebopsoriasis. The lesions were itchy in 13 (86.7%) of patients and the disease was considered severe in 7 (46.7%). Nail involvement, mainly onychorrhexis, was seen in 3 (20%) of patients. The joints were not affected in any patient with HIV-associated psoriasis.
Patients were mainly treated with moderately potent topical steroids and various concentrations of salicylic acid ointments. Ichthammol or coal tar preparations were used in 33 (15.1%), depending on availability. Topical calcipotriol was very expensive and not available and used for only 3 (1.3%) of patients. Methotrexate was the only systemic medication available and was used in 27 (12.4%) of patients, 85% of whom had severe disease. Betamethasone dipropionate solution together with a coal tar shampoo (T-gel) or other shampoo was used for all patients with scalp psoriasis. The median duration of follow-up was only 1.3 months– up to a third of patients did not come back after the first visit while one patient with mild psoriasis was seen in the clinic for 15 years.
| Discussion|| |
In two skin clinics in Kaduna, North-West Nigeria, 0.6% of patients presenting with new skin disease over a 20-year period were diagnosed with psoriasis. These also constituted 0.8% of patients with non-infectious skin disease. In two previous reports from similar clinics in the same city and in Zaria, 82 km away, between 1975 and 1984, Jacyk and Obasi reported that 78/9806 (0.8%) and 44/5250 (0.8%), respectively, of all patients with new skin disease, had psoriasis., Reports from other parts of Nigeria show a similar pattern: In southwest Nigeria, Ogunbiyi et al. reported that 10/1091 (0.9%) of patients with skin disease seen in Ibadan between 1994 and 1998 had psoriasis while Ayanlowo and Akinkugbe reported that 124/11,015 (1.1%) of patients with skin disease in a clinic in Lagos were diagnosed with psoriasis. Nnoruka reported that 16/2871 (0.6%) of patients with skin disease in Enugu in southeast Nigeria between 1999 and 2001 had psoriasis. Our result suggests there has not been much change in the proportion of patients seen with psoriasis in our clinics in Kaduna in the last 20 years compared to over 30 years ago despite the constant availability of a dermatologist in this period. Furthermore, our results and those from other parts of Nigeria,,,, and Africa confirm the variation in the relative incidence of psoriasis even in the same country and region, a phenomenon also noted worldwide. This is also consistent with a reported stable or slightly decreasing incidence of psoriasis reported in Europe, Asia and North America. Reports of rates of psoriasis in new patients in the West African sub-region (0.025%–0.6%) are similar to those of Nigeria and Central Africa (0.3%–0.8%) but lower than those of East Africa (1.9%–3.5%) or Southern Africa (1%–4%). Leder and Farber, in a comprehensive review of the factors-genetics, ethnicity, weather-which might contribute to this variable incidence of psoriasis in sub-Saharan Africa, have postulated that a so-far unidentified genetic factor might explain these differences. Although population studies have not been conducted in much of Africa to establish the true incidence and prevalence of psoriasis, our results and those of others suggest that psoriasis is far less common than in the rest of the world including Europe, North America and Australia. Namazi has suggested that a diet made predominantly of maize may partly explain this apparent low incidence and prevalence of psoriasis, although, we believe, this is likely to apply more to East and Southern Africa than West Africa, where the staple diet is different.
The male preponderance noted in our patients has also been reported in other studies in Nigeria,, and in West Africa, Saudi Arabia and India but not in Brazil, Western Europe and America, where psoriasis is said to occur equally among the sexes or is slightly more common in females. It is noteworthy that Enigbokan recently found that psoriasis affected slightly more females than males in Ibadan, Nigeria. Males have more severe disease than females in our study, as was also observed by Enigbokan and Hägg et al. in Sweden, and are, therefore, more likely to present to outpatient skin clinics than females, who otherwise form majority of patients in our clinics.,, Majority of our patients developed psoriasis in their teenage years or the second or third decades of life and is similar to Obasi's report and to findings in the south of Nigeria,, Abidjan, Cote d'Ivoire and in other parts the world.,,, The relative proportion of the clinical types of psoriasis is also as reported elsewhere,,,,,, with plaque psoriasis occurring in most patients. Psoriasis presents earlier in females than males as noted in our patients and those of others, and is believed to be hormone related (females reach puberty earlier) or to the differential effect of gender on psoriasis HLA susceptibility genes. The areas of involvement of psoriasis are also no different from previous reports although Ayanlowo and Akinkugbe did not mention genital involvement in their report while Obasi did not say how many of his patients presented with genital lesions and Enigbokan reported only one patient had genital involvement. Genital involvement in psoriasis is far more common than appreciated– up to 40% of patients may have genital lesions-and patients may not volunteer the information unless specifically asked; yet it may cause soreness, itching, discomfort and embarrassment leading to sexual difficulties and impairment of quality of life. Involvement of other body parts is similar in males and females in our study except the torso and lower limbs where males are more frequently affected reflecting the more severe disease in males. Our study also shows that the nails were affected in some form in more than a quarter of patients although the changes were mild. HIV-related psoriasis occurred in 7% of our patients and its clinical characteristics were different from those without the disease: They were predominantly male and had a shorter duration and more severe disease, including a greater proportion (40%) with erythrodermic psoriasis, a phenomenon also observed by Morar et al. in South Africa. In fact, the severity of the skin disease prompted HIV testing in most of these patients and reflected a worsening immune dysfunction. We have made fewer diagnoses of HIV-related skin disease in the past 10 years than previously-no patient was seen with HIV-associated psoriasis since 2014-and we believe this is due to early diagnosis of HIV now being made and prompt treatment instituted. HIV infection is believed to directly trigger psoriasis through excessive antigenic stimulation or as a source of superantigens, which initiate a cascade of innate and adaptive immune responses leading to the inflammation characteristic of psoriasis.
Psoriasis was classified as mild in most of our patients as in previous reports in the same area,, and a recent report from Ibadan and Cote d'Ivoire, and appeared less severe than in high incidence countries, although Ayanlowo and Akinkugbe also noted that 44% of their patients had severe disease (>10% BSA involved). The milder nature of psoriasis is reflected in the proportion of patients treated with systemic medications: Only 12% of our patients required treatment with methotrexate.
Psoriatic arthritis was very rare in our patients, a point also noted in previous studies in Nigeria,,, and other sub-Saharan African countries probably because the disease is milder. It is also possible that arthritis is underdiagnosed in our patients as it develops decades after the onset of psoriasis and patients may not return for follow-up because of the milder nature of their disease; up to a third of our patients did not return after the first visit. A definite family history of psoriasis was present in 13.2% of our patients in whom this information was available, which was a little more than in Ayanlowo's patients (8.1%) and three times more than Obasi's (4.5%) but far less than what was reported in high incidence countries, where a family history of psoriasis is reported in up to 52% of patients.
Our study is retrospective with its well-known limitation– patients with less severe disease are less likely to present to clinics-but we believe it sheds light on the relative incidence and clinical characteristics of psoriasis in northern Nigeria over a long period. Population-based studies to ascertain the true incidence and prevalence of psoriasis and associated factors in sub-Saharan Africa are virtually non-existent, and need to be carried out and will answer some questions on why this disease appears to be so much uncommon here than elsewhere.
| Conclusion|| |
Our study indicates that psoriasis remains a rare and milder disease in northern Nigeria than has been reported in countries with a higher incidence and prevalence of the disease, affects far more male patients than female patients, has fewer nail and joint involvement, and family history of the disease is infrequent. It is, however, similar in other respects to the disease reported elsewhere such as the early onset of the disease in the majority of patients, the predominance of plaque psoriasis, and more severe disease in males. HIV infection was an important trigger of the disease early on but declined with the availability of early diagnosis and treatment.
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Conflicts of Interest
There are no conflicts of interest.
| References|| |
Griffiths CE, Armstrong AW, Gudjonsson JE, Barker JN. Psoriasis. Lancet 2021;397:1301-15.
Gelfand JM, Troxel AB, Lewis JD, Kurd SK, Shin DB, Wang X, et al.
The risk of mortality in patients with psoriasis: Results from a population-based study. Arch Dermatol 2007;143:1493-9.
Ferreira BI, Abreu JL, Reis JP, Figueiredo AM. Psoriasis and associated psychiatric disorders: A systematic review on etiopathogenesis and clinical correlation. J Clin Aesthet Dermatol 2016;9:36-43.
Rapp SR, Feldman SR, Exum ML, Fleischer AB Jr., Reboussin DM. Psoriasis causes as much disability as other major medical diseases. J Am Acad Dermatol 1999;41:401-7.
Brezinski EA, Dhillon JS, Armstrong AW. Economic burden of psoriasis in the United States: A systematic review. JAMA Dermatol 2015;151:651-8.
Rachakonda TD, Schupp CW, Armstrong AW. Psoriasis prevalence among adults in the United States. J Am Acad Dermatol 2014;70:512-6.
WHO. Global Report on Psoriasis. Geneva: World Health Organization; 2016.
Parisi R, Iskandar IY, Kontopantelis E, Augustin M, Griffiths CE, Ashcroft DM, et al.
National, regional, and worldwide epidemiology of psoriasis: Systematic analysis and modelling study. BMJ 2020;369:m1590.
Leder RO, Farber EM. The variable incidence of psoriasis in sub-Saharan Africa. Int J Dermatol 1997;36:911-9.
Nnoruka EN. Skin diseases in south-east Nigeria: A current perspective. Int J Dermatol 2005;44:29-33.
Ayanlowo O, Akinkugbe A. Clinical pattern of psoriasis seen at a tertiary institution in Nigeria. J Clin Sci 2016;13:137-42. [Full text]
Jacyk WK. Psoriasis in Nigerians. Trop Geogr Med 1981;33:139-42.
Obasi OE. Psoriasis vulgaris in the Guinea Savanah region of Nigeria. Int J Dermatol 1986;25:181-3.
Strober B, Ryan C, van de Kerkhof P, van der Walt J, Kimball AB, Barker J, et al.
Recategorization of psoriasis severity: Delphi consensus from the International Psoriasis Council. J Am Acad Dermatol 2020;82:117-22.
Ogunbiyi AO, Daramola OO, Alese OO. Prevalence of skin diseases in Ibadan, Nigeria. Int J Dermatol 2004;43:31-6.
Iskandar IY, Parisi R, Griffiths CE, Ashcroft DM, Global Psoriasis Atlas. Systematic review examining changes over time and variation in the incidence and prevalence of psoriasis by age and gender. Br J Dermatol 2021;184:243-58.
Namazi MR. Why is psoriasis uncommon in Africans? The influence of dietary factors on the expression of psoriasis. Int J Dermatol 2004;43:391-2.
Elbehri A, Kaminski J, Koroma S, Iafrate M, Benali M. West Africa staple food systems: An overview of trends and indicators of demand, supply, and trade. In: Elbehri A, editor. Rebuilding Africa's Food Potential. Rome: FAO/IFAD; 2013.
Mamadou K, Vagamon B, Isidore KY, Joseph EL, Patrice GI, Almamy D, et al
. Psoriasis among African blacks: The Abidjan experience of 17 years. J Clin Exp Dermatol Res 2015;6:291.
Fatani MI, Abdulghani MH, Al-Afif KA. Psoriasis in the eastern Saudi Arabia. Saudi Med J 2002;23:213-7.
Dogra S, Yadav S. Psoriasis in India: Prevalence and pattern. Indian J Dermatol Venereol Leprol 2010;76:595-601.
] [Full text]
Porto Ferreira C, Martins CJ, Issa PR, de Vasconcellos Carvalhaes de Oliveira R, Da-Cruz AM. Psoriasis affects individuals of African descent and white Brazilians similarly. Actas Dermosifiliogr 2010;101:230-4.
Enigbokan OA. Clinicopathologic Features and Quality of Life of Patients with Psoriasis in Ibadan, Nigeria (Unpublished Dissertation). National Postgraduate Medical College of Nigeria (Internal Medicine); 2017.
Hägg D, Sundström A, Eriksson M, Schmitt-Egenolf M. Severity of psoriasis differs between men and women: A study of the clinical outcome measure psoriasis area and severity index (PASI) in 5438 Swedish Register Patients. Am J Clin Dermatol 2017;18:583-90.
Yahya H. Change in pattern of skin disease in Kaduna, north-central Nigeria. Int J Dermatol 2007;46:936-43.
Atraide DD, Akpa MR, George IO. The pattern of skin disorders in a Nigerian tertiary hospital. J Public Health Epidemiol 2011;3:177-81.
Levi SS, Ramot Y. Gender differences in psoriasis. In: Tur E, Maibach HI, editors. Gender and Dermatology. Cham: Springer International Publishing AG; 2018.
Meeuwis KA, Potts Bleakman A, van de Kerkhof PC, Dutronc Y, Henneges C, Kornberg LJ, et al.
Prevalence of genital psoriasis in patients with psoriasis. J Dermatolog Treat 2018;29:754-60.
Hariram P, Mosam A, Aboobaker J, Esterhuizen T. Quality of life in psoriasis patients in KwaZulu Natal, South Africa. Indian J Dermatol Venereol Leprol 2011;77:333-4.
] [Full text]
Morar N, Dlova NC, Mosam A, Aboobaker J. Cutaneous manifestations of HIV in Kwa-Zulu Natal, South Africa. Int J Dermatol 2006;45:1006-7.
Morar N, Willis-Owen SA, Maurer T, Bunker CB. HIV-associated psoriasis: Pathogenesis, clinical features, and management. Lancet Infect Dis 2010;10:470-8.
Akpabio AA, Olaosebikan BH, Adelowo OO. Psoriatic arthritis in Nigeria: Case series and literature review. J Clin Rheumatol 2018;24:183-7.
Bedaiwi M, Al-Homood IA, El-Garf A, Uthman I, Sunna N, Nassier R, et al.
Disease burden and treatment challenges of psoriatic arthritis in Africa and the Middle East. Rheumatol Int 2019;39:1321-9.
Mallbris L, Larsson P, Bergqvist S, Vingård E, Granath F, Ståhle M. Psoriasis phenotype at disease onset: Clinical characterization of 400 adult cases. J Invest Dermatol 2005;124:499-504.
[Figure 1], [Figure 2]
[Table 1], [Table 2]