## 3 Results
### Management of Erythroderma  
Regardless of the cause, in the group of patients with erythroderma, systemic antihistamines (146 cases, 71.57%) were the most frequently selected therapeutic approach, followed by systemic steroids (132 cases, 64.71%). The subsequent options included antibiotics (77 cases, 37.75%), methotrexate (60 cases, 29.41%), cyclosporine A (37 cases, 18.14%), phototherapy (35 cases, 17.15%), acitretin (16 cases, 7.84%) and azathioprine (2 cases, 0.98%). The results highlighted the significant differences in the administration of systemic steroids between the groups (\(p<0.001\)). In patients with psoriatic erythroderma, systemic steroids were used less frequently than in patients with other erythroderma (\(p<0.001\)). Systemic antihistamines were predominantly used in AD (96.27%), drug-induced (86.36%), eczema (80.95%), and idiopathic (79.49%) erythroderma. A statistically significant difference was observed in the use of systemic antihistamines between groups (\(p<0.001\)). Systemic antihistamines were more frequently used in the aforementioned groups than in CTCL and psoriasis. Regarding phototherapy, no significant differences were observed among the examined groups (\(p>0.05\)). MTX was most frequently used among CTCL (59.26%) and psoriasis (42.86%) patients. Statistically significant differences were found in the usage of MTX medication between the psoriasis group and the groups of patients with idiopathic erythroderma, AD, eczema, and drug-induced skin reactions (\(p<0.01\)). Moreover, statistically significant differences were found between CTCL and AD and drug-induced skin reaction groups (\(p<0.01\)). However, no statistically significant differences in the usage of MTX were observed among the remaining groups. Cyclosporine A was the most common treatment option for patients with AD (\(n=14\); 51.85%). There were statistically significant differences between groups (\(p<0.001\)). This therapy was more frequently used in the AD group compared with the pairs of all other erythroderma causes. There was also a significant difference in systemic antibiotic use between groups (\(p=0.006\)). This therapeutic option was frequently used in psoriasis, AD, and drug-induced erythroderma, while in CTCL and eczema-caused erythroderma, antibiotics were administered sparingly. Patients with elevated CRP and neutrophil levels were significantly more likely to receive antibiotics. Detailed data on the management of erythroderma in each group is shown in Figure 1.  
Patients in our study did not receive biological treatment during hospitalization. However, several patients were treated with biologics before hospital admission or were subsequently enrolled in a biologic treatment program. One pediatric patient in our sample received biological treatment (dupilumab) for atopic dermatitis before hospitalization. Two patients with psoriasis vulgaris were treated with biologics. One received ustekinumab, and in the other case adalimumab was initially administered, but due to an unsatisfactory response, the drug was changed to ustekinumab with positive results. One patient with psoriatic arthritis was treated with secukinumab. The authors conducted a database search of patients enrolled in the biologic treatment program to determine whether patients included in the study were subsequently recruited into the program. Four patients from our study were identified as part of the biologic therapy program: three with psoriasis vulgaris and one with atopic dermatitis. One patient with psoriasis began treatment with ustekinumab in 2015 with a BSA of 91 and a PASI of 35.4. The last follow-up in 2023 provided information on improvement to a BSA of 0.1 and a PASI of 2.5. In one case, adalimumab treatment in 2017 was given to a patient with a BSA of 35 and a PASI of 18.9, but due to lack of the expected response, the decision was made to switch medications. The patient received risankizumab with a BSA response of 0.5 and a PASI of 1.6.