## 4 Discussion  
Our cross-sectional, binational study, including a wide spectrum of clinical subtypes of psoriasis, demonstrated the influence of the disease severity on the QoL, irrespective of the particular psoriasis variant. The mean DLQI scoring in our cohort of patients was 12.7 points, indicating on average a large effect of psoriasis on patients' QoL. In the past, many researchers also investigated the QoL of psoriasis patients and obtained similar results demonstrating that psoriasis is a chronic dermatosis which exerts a profound effect on patients' well-being [21; 22; 23; 24; 25]. However, in other studies, physicians were focused on various factors that might play a crucial role in lowering the QoL such as the presence of pruritus, occupation of the anogenital area by the disease or visibility of skin lesions [24; 25; 26; 27]. Data comparing QoL in different clinical subtypes of psoriasis are quite limited, as the previously published reports are predominated by the patients suffering from plaque-type \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & & \multicolumn{2}{c}{**Mean**} & \multirow{2}{*}{\(p\)} & \multicolumn{2}{c}{**Mean**} & \multirow{2}{*}{\(p\)} & \multicolumn{2}{c}{**Mean**} & \multirow{2}{*}{\(\mathbf{10}\)**-PSS**} & \multirow{2}{*}{\(\mathbf{p}\)} \\  & & \(\mathbf{NRS_{max}}\) & & & & & & \\ \hline \multirow{4}{*}{Problems in falling} & Almost always & 7.3 \(\pm\) 2.2 & \multirow{4}{*}{\(<\)0.001} & 6.0 \(\pm\) 2.5 & 13.5 \(\pm\) 3.5 & \multirow{4}{*}{\(<\)0.001} \\ \cline{2-3} \cline{5-8}  & Rarely & 5.5 \(\pm\) 2.2 & & 4.1 \(\pm\) 2.1 & & 9.4 \(\pm\) 3.1 & \\ \cline{2-3} \cline{5-8}  & Never & 3.3 \(\pm\) 2.7 & \multirow{4}{*}{\(<\)0.001} & 2.6 \(\pm\) 2.5 & & 5.8 \(\pm\) 3.8 & \\ \cline{2-3} \cline{5-8}  & Almost every night & 7.3 \(\pm\) 2.3 & \multirow{4}{*}{\(<\)0.001} & 6.1 \(\pm\) 2.6 & 13.3 \(\pm\) 3.4 & \multirow{4}{*}{\(<\)0.001} \\ \cline{2-3} \cline{5-8}  & Rarely & 5.6 \(\pm\) 2.3 & & 4.2 \(\pm\) 2.2 & & 9.7 \(\pm\) 3.6 & \\ \cline{2-3} \cline{5-8}  & Never & 3.8 \(\pm\) 2.7 & \multirow{4}{*}{\(<\)0.001} & 2.8 \(\pm\) 2.4 & & 6.5 \(\pm\) 3.9 & \\ \hline \multirow{4}{*}{Use of sleeping medication} & Almost every day & 8.2 \(\pm\) 1.7 & \multirow{4}{*}{\(<\)0.001} & 7.4 \(\pm\) 2.5 & 15.1 \(\pm\) 3.0 & \multirow{4}{*}{\(<\)0.001} \\ \cline{2-3} \cline{5-8}  & Rarely & 6.4 \(\pm\) 2.5 & & 4.8 \(\pm\) 2.3 & & 10.7 \(\pm\) 3.5 & \\ \cline{2-3} \cline{5-8}  & Never & 4.7 \(\pm\) 2.8 & & 3.6 \(\pm\) 2.6 & & 8.3 \(\pm\) 4.5 & \\ \hline \end{tabular}
\end{table} 
Table 4: Comparison of pruritus intensity in relation to the sleeping problems (10-PSS—10-item Pruritus Severity Scale, \(\mathrm{NRS_{average}}\)—average Numerical Rating Scale, \(\mathrm{NRS_{max}}\)—maximal Numerical Rating Scale). \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Large-**} & \multicolumn{2}{c}{**Small-**} & \multicolumn{2}{c}{**Gutate**} & \multicolumn{2}{c}{**Palon-**} & \multicolumn{2}{c}{**Poorasis**} & \multicolumn{2}{c}{**Inverse**} & \multicolumn{2}{c}{**Erhydrodermic**} & \multicolumn{2}{c}{**Palmoplantar**} & \multicolumn{2}{c}{**Generalized**} \\  & \multicolumn{2}{c}{**Plaque**} & \multicolumn{2}{c}{**Poorasis**} & \multicolumn{2}{c}{**Poorasis**} & \multicolumn{2}{c}{**Poorasis**} & \multicolumn{2}{c}{**Scalp**} & \multicolumn{2}{c}{**Poorasis**} & \multicolumn{2}{c}{**Poorasis**} & \multicolumn{2}{c}{**Poorasis**} & \multicolumn{2}{c}{**Poorasis**} \\ \hline \multirow{4}{*}{DLQI vs.} & \(\mathbf{NRS_{max}}\) & \(\mathbf{\rho=0.51}\), & \(\mathbf{\rho=0.17}\), & \(\mathbf{\rho=0.18}\), & \(\mathbf{\rho=0.27}\), & \(\mathbf{\rho=0.52}\), & \(\mathbf{\rho=0.17}\), & \(\mathbf{\rho=0.15}\), & \(\mathbf{\rho=0.43}\), & \(\mathbf{\rho=0.48}\), \\  & \(\mathbf{p<0.001}\)posoriasis, which is the most common one. Here, we aimed to analyze whether the level of QoL impairment may differ between various psoriasis variants. We also compared included participants with various psoriasis subtypes regarding sleeping problems.