Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is an autoimmune encephalopathy characterized by neuropsychiatric symptoms, autonomic instability, and abnormal movements. Most children who undergo tumor removal and receive appropriate immunosuppressants have substantial neurological improvement. We report a 14-year-old girl with relapsing anti-NMDAR encephalitis who presented with paroxysmal tingling and weakness of the right lower limb. Despite long-term prophylaxis with immunotherapy (azathioprine), tumefactive demyelinating lesion and multifocal subcortical white matter lesions were identified on magnetic resonance imaging, which improved after high doses of steroid therapy. There may be overlap between the clinical manifestations of anti-NMDAR encephalitis and acquired demyelination syndromes in children.

Allergic disorders and headache are both common in pediatric populations. Chronic allergic disorders may affect sleep leading to chronic daily headaches. Poor controlled allergies may cause neurogenic inflammation that may be a predisposing factor to migraine headaches. We hypothesized that a higher prevalence of headaches may be found in children with allergy compared with those without allergy. Patients with either multiple allergic disorders or with poorly controlled allergic symptoms may be associated with headaches, especially migraine headaches. This study aimed to examine (1) the prevalence of headache in allergic children and (2) the association between allergic diseases and headache. Patients with allergic diseases and nonallergic children as control were recruited in the pediatric outpatient clinic of Naresuan University Hospital between January 2017 and January 2018. A neurological examination was performed by a pediatric neurologist. The questionnaire consisted of the pediatric headache symptom checklist and the items for evaluation of allergy control status. The diagnosis and classification of headache were based on the International Classification of Headache Disorders-3 criteria. The results were analyzed using the Student's t-test, chi-squared tests, odds ratios, and 95% confidence interval. One hundred fifty-five subjects were enrolled in our study, of which 85 subjects (54.8%) were diagnosed with allergic diseases. The allergic group had a significantly higher prevalence of headache than the control group (37 [43.5%] vs. 19 [27.1%], p = 0.035). The allergic group also had a significantly higher prevalence of migraine and probable migraine headache than the control group (23 [27.06%] vs. 7 [10%], p = 0.007). The prevalence of headache did not increase in subjects who had more than one allergic disease. There was no association between the control of allergy and headache. The present study showed that allergic diseases were associated with increased prevalence of headache and migraine in children. However, the control of allergic symptoms and the number of allergic diseases were not associated with headache. The physicians should be aware of headache in allergic patients and give appropriate treatment. Further study would be to identify specific biomarkers for the development of better treatment in these comorbid diseases.