Clinical st ud y 
K E Y 
WORDS 
children 
psoriasis, 
age, clinical 
types, 
precipitating 
factors, 
Latvia 
Study on children psoriasis in Latvia 
Study on children psorias-is in Latvia 
S. Sigure and A. Rubins 
ABSTRACT 
Objective. The aim of the study was to evaluate psoriasis morbidity among children in Latvia. 
Materials and methods. 252 psoriatic children, 3 to 18 years old children, were surveyed using a ques-
tionnaire developed for this study. Data on the course of the disease, skin involvement and further clini-
cal symptoms and signs were registered. They were evaluated using PASI system. Data were analyzed 
using the computerized programs (MS Excel 98 and SPSS). 149 girls (59 %) and 103 boys (41 %) were 
included in the study, the patients originated from different regions of Latvia. 
Results. Children aged 11 to 15 years suffered from psoriasis (46%) most frequently. 
Psycho-emotional stress 198 (79%), viral and bacterial infections 119 (47%) were the most frequent 
promoting factors. In 26% of patients a family history of psoriasis was noted. Psoriasis vulgaris was 
diagnosed in 57 % of patients, and psoriasis exsudativa in 27 %. Mean PASI index was 12.92. 
Conclusion. Psoriasis seems to be quite frequent in children in Latvia. 
Introduction 
Psoriasis affects 1-3% of world's population. In the 
countries of Northern Europe the incidence of psoria-
sis is particularly high (1 ,2). It is a rnultifactorial dis-
ease. Pathogenetically it is related to the genetically de-
terrnined keratinisation process, w hich rnanifests itself 
as hyperproliferation of epidermal keratinocytes and dis-
turbecl normal clifferentiation process of epiderrnal cells. 
In the early pluse neutrophil leucocytes appear in epi-
clerrnis and activatecl T lymphocytes in dermis (5,6) . 
Factors precipitating psoriatic eruption include local 
traurna , infections (streptococcal, particularly in chil-
dren) , stress , enclocrine factors, clrugs, radiation etc. 
(1 ,4,7,8 ,9). Psoriasis is dividecl into two types. Type I 
psoriasis , which is HLA Cw6 positive (arouncl 65% of 
ali psoriasis patients), begins in adolescence . Type II 
psoriasis, which is HLA Cw6 negative, clevelops later 
and is connected neither with HLA sy'stem nor family 
heredity. 
H. Takernatsu et al. describecl increasecl levels of 
HLA antigens B13, B17, B27, B37 etc. in psoriasis pa-
tients . It testifies the link between psoriasis ancl differ-
ent HLA systern proteins (3 ,7 ,10). 
Acta Dermatoven APA Vol 11, 2002, No 2 ---- -------------- 4$ 
Study on children psoriasis in Latvia 
Table 1. Distribution of children by sex and age 
(n=252). 
Age groups Boys Girls Total % 
(years) 
3-5 6 3 9 3,57 
6-10 23 29 52 20,6 
11-15 49 68 117 46 
16-18 25 49 74 29 
Severa! authors have stressed that psoriasis is a rather 
frequent disease in Latvia. 
Data from literature show that the medium age of 
psoriasis patients is between 10 and 30. However, dis-
ease can start at any age, even in infancy (2). Epide-
miologic studies revealed that in 37 % of patients pso-
riasis appeared at the age of 20, in 27 o/o at the age of 15, 
in 10 o/o at the age of 10, in 6.5 o/o eruptions manifest 
before the age of five, and in 2% at the age of two (1). 
Psoriasis is equally distributed among adult male and 
female patients. Girls are affected more often than boys, 
the ratio being 2: 1 (1 ,4). 
In Latvia the psoriasis morbidity among children 
younger then 18 has not been studied u p to now. 
The objectives of the present investigation were: 
1) To find the prevalence of psoriasis among children 
and adolescents under 18 in Latvia; 
2) To assess the most common precipitating factors; 
3) To find out the most common clinical forms; and 
4) To evaluate the extent and intensity of psoriatic le-
sions by PASI index. 
Materials and methods 
252 patients under the age of 18 were studied. The 
data were entered in specially designed questionnaires. 
It was devised according the internationally approved 
criteria, and it was adapted to the situation in Latvia. 
The fo llowing data were registered: age (18 years and 
less), gencler, address, vaccination protocol , allergic re-
actions, prior infections, interna! pathologies, family his-
to1y of psoriasis and of other chronic skin conditions, 
and interna! diseases. The clata on factors precipitating 
psoriasis , age at which psoriasis was diagnosed, extent 
of skin lesions, clinical form, complications ancl treat-
ment used were also collectecl. 
The course of psoriasis, extent of lesions ancl inten-
sity of clinical symptoms were evaluated using PASI 
system. Points O to 3 inclicate a mild PASI, 3 to15 - mocl-
erate ancl more than 15 - a severe PASI score. 
Data were analyzed using MS Excel 98, SPSS com-
puter programs. 
Table 2. PASI index in children with psoriasis by age (n=252). 
Age N Minimum Ma.ximum Mean Std.Statistic 
Statistk Std. Error 
3 1 5,0 5,0 5,000 
4 1 12,0 12,0 12,000 
5 7 2,4 21,6 13,457 2,862 7,573 
6 9 0,6 29,0 11 ,456 2,718 8,155 
7 12 1,8 23,0 13,083 1,863 6,453 
8 9 0,5 39,2 14,533 4,565 13,695 
9 15 3,6 22,2 10,467 1,345 5,209 
10 7 9,4 18,6 14,929 1,241 3,283 
11 21 6,0 24,S 14,329 ,981 4,498 
12 19 0,5 26,0 12,974 1,787 7,790 
13 20 0,5 32,6 15,055 2,162 9,671 
14 33 0,5 23,4 12,588 1,244 7,144 
15 24 0,5 34,8 11 ,079 1,833 8,981 
16 34 0,6 37,0 14,244 1,352 7,883 
17 21 0,5 22,0 11 ,429 1,296 5,938 
18 19 0,5 24,7 12,579 1,414 6,166 
Tota! 252 
C lini cal st udy 
46 ------ - - - -------- - - - --------------Acta Dermatoven APA Vol 11, 2002, No 2 
Cli n i cal st u dy 
30 
~ 25 
c 
~ ·-; 
C. 
20 
o 
t. 15 
.C 
E 
:, 
z 10 
5 
o 
4 
250 
200 
~ 
~ l 150 
o 
t. 
.C 
100 E :, 
z 
50 
o 
Psoriasis 
ln family 
5 6 7 8 9 10 11 12 13 14 15 16 17 18 
Age In years 
I• boys Oglrls 
Figure 1 . Distribution of children by age (n=252). 
Results 
The total number of 252 patients were studied and 
interviewed. Out of these, 103 ( 40.87%) were boys , 149 
(59.13%) were girls. Girls were more often affected with 
psoriasis, particularly at the age of 14 to l 7; boys were 
more often affected between 13 to16 years. 
Distribution of children by age group and gender 
are summarized in Figure 1. 
The studied children were divided in 4 groups by 
gender and age (Table l.). There were 9 patients (3 .6%) 
under five years, 52 (20.6%) between six to ten years, 
117 C 46%) between 11 to 15, and 7 4 (29%) in the age 
Figure 2. Psoriasis precipitating factors among 
children under age of 18 (n=252). 
198 
3 
Viral and Emotional Allergyto Drugs Radiation 
bacterial stress food and 
infections medicines 
Acta Dermatoven APA Vol 11, 2002, No 2 
Study on children psoriasis in Latvia 
group 16 to 18 years. The majority of children were in 
age group 11 to15 years (46%) . 
The most common precipitating factors found in 
children in this study were (Figure 2): psycho-emotional 
stress 198 (78.57%), vira! and bacterial infections 119 
(47.2%) . Evidence of psoriasis in family members was 
found in 66 (26%) of patients . Out of them 40 (60.6%) 
inherited the disorder from fa thers' side, 21 (31.8%) from 
mothers' side, 4 (6 .1%) from both parents . Psoriasis in 
siblings was found in five instances - (7 .6%) children. 
Some patients had severa! precipitating factors. 
The following clinical forms of psoriasis were ob-
served: psoriasis vulgaris in 143 (56. 75%) patients, pso-
riasis exsudativa in 67 (26.59%), psoriasis pustulosa in 
6 (2.4%), psoriasis guttata in 28 (11.1 %), psoriasis inversa 
in 4 (1.6%), psoriatic e rythroderma in 4 (1.6%) patients, 
while three of them also had arthritis . Damage of the 
nails was noted in 3 (2,9%) male patients (Figure 3). 
As it is shown in Figure 4, psoriasis in children ex-
acerbates more often during winter. The exacerbation 
in winter was observed in 82 girls and 74 boys, while in 
summer the exacerbation was noted in 27 girls and 13 
boys, mixed form in 40 girls and 16 boys. 
Among the studied psoriasis patients , 138 girls and 
90 boys had psoriatic eruptions on the face and on scalp. 
In this study, evaluation of course of disease, the extent 
of psoriatic damage, and intensity of clinical symptoms 
(erythema, scaling , and infiltration) were done using 
PASI scale. Mean PASI score for all 252 studied patients 
was 12.92 (standard error ± 0.47, SD 7.48, dispersion 
amplitude 38.7, minimum 0.5, max 39.2). PASI in pso-
riasis affected children by age groups is summarized in 
Table 2. 
The following co-morbidity was found in the stud-
ied patients: 14 (5.55%) neurological ailments, includ-
ing organic damage of central nervous system in three 
and epilepsy in one , nocturnal enuresis in seven, and 
eight (3 .17%) with gastro-duodenitis (Figure 5). 
Discussion 
Analysis of clata by age revealed, that the age group 
11 to 15 is most often affected. Girls are affected twice 
as often as boys in ali age groups . Similar data have 
been shown in studies performed in other countries (1). 
A study performed at the Stanford Un.iversity Medica] 
School ( 4), which included 5,600 patients and the Nor-
wegian Psoriasis stucly (1 1) showed, that girls are more 
often affected by psoriasis than boys by the ratio of 2: 1. 
Analysis by age showed that girls are most often af-
fectecl at the age of 14 to17, and boys at the age of1 3 
47 
Study on children psoriasis in Latvia 
to 16. 
Similar data about importance of stress, psycho 
trauma, infection, particularly streptococcal, of this dis-
ease in children have been observed in other studies 
(1 ,11 ,12). 
Some studies revealed heredity in up to 40 % of chil-
dren with psoriasis (13 ,14,16). In our study, heredity 
was found to be more often linked to the father's side . 
Similar conclusions were obtained in the Mi..inster's Pso-
riasis study (15). 
This study showed that the most common clinical 
form of childrens' psoriasis in Latvia is psoriasis vul-
garis, followed by psoriasis exsudativa and guttata 
forms . Other studies (4, 12) revealed that children most 
often suffer from psoriasis vulgaris, which is followed 
by psoriasis guttata. In our as well as in other studies 
psoriatic e1ythroderma was rare (4,13). 
Analysis by PASI scale showed similar pattern in dif-
ferent age groups, which means that psoriasis in chil-
dren in Latvia affects large areas of the body. 
Co-morbiditywas found in a few patients. The most 
frequent accompanying diseases were neurological (5.5 
%) . Neurological impairments have been found more 
frequently among psoriatic patients in other studies (13). 
Conclusions: 
- Psoriasis most often affects children at the age of 11 
tol5 years, 
- 26 % cases have family history of psoriasis, 
- the most common clinical form is psoriasis vulgaris, 
- the main psoriasis precipitating factor is psycho-emo-
tional stress , 
- psoriasis affected large areas as shown by PASI val-
ues, it was similar in all age groups. 
Understanding of the extent of morbidity and pre-
disposing factors at an early age could be helpful in 
preventing complications in later years and thus, im-
prove the quality of life. 
Clinical study 
• vulgaris 
lli exsudativa 
O pustuloza 
O guttata 
• inversa 
• erythrodermia 
vulgaris (56%) 
Figure 3. Clinical forms of psoriasis among 
children under age of 18 (n=252). 
90 
82 
80 
"' E 70 .. 
~ 
C. 60 o 
iii 50 .o 
E 
:, 40 z 
30 
20 
10 
o 
winter summer 
1 • boys • girls 
Figure 4. Distribution of psoriasis by seasons 
among children under age of 18 (n=252). 
Figure 5. Co-morbidity among children (less 
than 18 years of age) with psoriasis (n=252). 
16 
14 
14 
.l!l 12 
C: .. 
10 ~ 
C. 8 
o 8 
iii 
.o 6 E 
:, 
C: 
4 
2 2 
2 
o 
mixed 
48 ---------- ---------------------------Acta Dermatoven APA Vol 11, 2002, No 2 
CI in i c a I s t u d y Study on children psoriasis in Latvia 
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AUTHORS' 
ADDRESSES 
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14. Akyshbaeva G, Rybkina L, Utepova A. Clinical and immunological features of psoriasis in children. J 
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17. Morris A, Rogers M, Fischer G, Williams K. Childhood Psoriasis: A Clinical Review of 1262 Cases. 
Pediatric Dermatology 2001; 18 (3): 188-98. 
Sanita Zigure, MD, Assistant Projessor, Dept Dermatovenereology, 
Children Clinical Hospital, Venibas gatve 4 5, Riga LV 105 O, Latvia 
Andris Rubins MD, PhD, Professor and Head Dept oj · 
Dermatovenereology, Latvian MedicalAcademy, Dzirciema str. 16,Riga 
LV1007, Latvia. 
Acta Dermatoven APA Vol 11, 2002, No 2 ---- ----------- - -- 49