Arachnophobia is a specific phobia brought about by the irrational fear of spiders and other arachnids such as scorpions. Signs and symptoms
People with arachnophobia tend to feel uneasy in any area they believe could harbour spiders or that has visible signs of their presence, such as webs. If arachnophobes see a spider, they may not enter the general vicinity until they have overcome the panic attack that is often associated with their phobia. Some people scream, cry, have emotional outbursts, experience trouble breathing, sweat and experience increased heart rates when they come in contact with an area near spiders or their webs. In some extreme cases, even a picture, a toy, or a realistic drawing of a spider can trigger intense fear. Reasons
Arachnophobia may be an exaggerated form of an instinctive response that helped early humans to survive or a cultural phenomenon that is most common in predominantly European societies. Evolutionary
An evolutionary reason for the phobia remains unresolved. One view, especially held in evolutionary psychology, is that the presence of venomous spiders led to the evolution of a fear of spiders, or made acquisition of a fear of spiders especially easy. Like all traits, there is variability in the intensity of fear of spiders, and those with more intense fears are classified as phobic. Being relatively small, spiders do not fit the usual criterion for a threat in the animal kingdom where size is a factor, but they can have medically significant venom and/or cause skin irritation with their setae.
Anti-NMDA receptor encephalitis is the most common autoimmune form, and is accompanied by ovarian teratoma in 58 percent of affected women 18–45 years of age. Encephalitis lethargica
Encephalitis lethargica is identified by high fever, headache, delayed physical response, and lethargy. Individuals can exhibit upper body weakness, muscular pains, and tremors, though the cause of encephalitis lethargica is not currently known. From 1917 to 1928, an epidemic of encephalitis lethargica occurred worldwide. Diagnosis
People should only be diagnosed with encephalitis if they have a decreased or altered level of consciousness, lethargy, or personality change for at least twenty-four hours without any other explainable cause. Diagnosing encephalitis is done via a variety of tests:
Brain scan, done by MRI, can determine inflammation and differentiate from other possible causes. EEG, in monitoring brain activity, encephalitis will produce abnormal signal. Lumbar puncture (spinal tap), this helps determine via a test using the cerebral-spinal fluid, obtained from the lumbar region. Blood test
Urine analysis
Polymerase chain reaction (PCR) testing of the cerebrospinal fluid, to detect the presence of viral DNA which is a sign of viral encephalitis. Prevention
Vaccination is available against tick-borne  and Japanese encephalitis  and should be considered for at-risk individuals. Post-infectious encephalomyelitis complicating smallpox vaccination is avoidable, for all intents and purposes, as smallpox is nearly eradicated. Contraindication to Pertussis immunization should be observed in patients with encephalitis.