The patient initially has nausea and vomiting, followed by respiratory distress, headache, and visual loss 18–48 hours after consumption. Without treatment, patients can go blind, and their pupils will dilate and stop reacting to light. Ethylene glycol, a component of automobile antifreeze, is a poison that is toxic to the whole body including the optic nerve. Consumption can be fatal, or recovery can occur with permanent neurologic and ophthalmologic deficits. While the visual loss is not very common, increased intracranial pressure can cause bilateral optic disc swelling from cerebral edema. A clue to the cause of intoxication is the presence of oxalate crystals in the urine. Like methanol intoxication, treatment is ethanol consumption. Ethambutol, a drug commonly used to treat tuberculosis, is notorious for causing toxic optic neuropathy. Patients with vision loss from ethambutol toxicity lose vision in both eyes equally. This initially presents with problems with colors (dyschromatopsia) and can leave central visual deficits. If vision loss occurs while using ethambutol, it would be best to discontinue this medication under a doctors supervision. Vision can improve slowly after discontinuing ethambutol but rarely returns to baseline. Amiodarone is an antiarrhythmic medication commonly used for abnormal heart rhythms (atrial or ventricular tachyarrhythmias). Most patients on this medication get corneal epithelial deposits, but this medication has also been controversially associated with NAION. Patients on amiodarone with new visual symptoms should be evaluated by an ophthalmologist. Tobacco exposure, most commonly through pipe and cigar smoking, can cause optic neuropathy.
Pityriasis alba is a skin condition, a type of dermatitis, commonly seen in children and young adults as dry, fine-scaled, pale patches on the face. It is self-limiting and usually only requires use of moisturizer creams.The condition is so named for the fine scaly appearance initially present (pityriasis), and alba (Latin for white) refers to the pallor of the patches that develop. The patches are not totally depigmented. Signs and symptoms
The dry scaling appearance is most noticeable during the winter as a result of dry air inside peoples homes. During the summer, tanning of the surrounding normal skin makes the pale patches of pityriasis alba more prominent.Individual lesions develop through 3 stages and sometimes are itchy:

Raised and red – although the redness is often mild and not noticed by parents
Raised and pale
Smooth flat pale patchesLesions are round or oval raised or flat, of 0.5–2 cm in size although may be larger if they occur on the body (up to 4 cm), and usually number from 4 or 5 to over 20. The patches are dry with very fine scales. They most commonly occur on the face (cheeks), but in 20% appear also on the upper arms, neck, or shoulders.The diagnostic differential should consider tinea and vitiligo amongst other causative factors. Cause
Any dermatitis may heal leaving pale skin, as may excessive use of corticosteroid creams used to treat episodes of eczema. The hypopigmentation is due to both reduced activity of melanocytes with fewer and smaller melanosomes.The cause of pityriasis alba is not known.