Here, the dust mites are beneficial as they return cotton to its original state after it has degraded by contact with bare skin.Dust mite eggs are freeze tolerant (−70 °C for 30 minutes); hatching can normally be prevented by exposure of fabrics to:
Direct sunlight for 3 hours or
Dry or wet heat of at least 60 °C (140 °F) for a minimum of 30 minutes.Dust mites drown in water.Good properties of anti-mite fabrics have been identified as being:
Thread count greater than 246. Pore size of between 2 and 10 micrometres. This will prevent dust mite faecal pellets that can be small as 10 µm. Allergen impenetrability >99%. Dust leakage of less than 4%. Breathability between 2 and 6 cm3 s−1 cm−2. Indoor climate
Allergy patients are advised to keep the relative humidity below 50%, if possible. Very few mites can survive if the humidity is less than 45% (at 22 °C (72 °F)). However, they can survive if the humidity is high just for an hour and a half per day, for example due to moisture released to the air when cooking food. Treatment
Allergen immunotherapy
Allergen immunotherapy (AIT, also known as desensitization or hypo-sensitization) is a treatment involved in administering the doses of allergens to accustom the body to substances that are generally harmless (pollen, house dust mites), thereby inducing specific long-term tolerance. Allergen immunotherapy is the only treatment that alters the disease mechanism.Immunotherapy can be administered orally (as sublingual tablets or sublingual drops), or by injections under the skin (subcutaneous).
There is no pharmacological test to differentiate between a first and second order neuron lesion. Dilation lag testIt is important to distinguish the ptosis caused by Horners syndrome from the ptosis caused by a lesion to the oculomotor nerve. In the former, the ptosis occurs with a constricted pupil (due to a loss of sympathetics to the eye), whereas in the latter, the ptosis occurs with a dilated pupil (due to a loss of innervation to the sphincter pupillae). In a clinical setting, these two ptoses are fairly easy to distinguish. In addition to the blown pupil in a CNIII (oculomotor nerve) lesion, this ptosis is much more severe, occasionally occluding the whole eye. The ptosis of Horner syndrome can be quite mild or barely noticeable (partial ptosis).When anisocoria occurs and the examiner is unsure whether the abnormal pupil is the constricted or dilated one, if a one-sided ptosis is present then the abnormally sized pupil can be presumed to be on the side of the ptosis. History
The syndrome is named after Johann Friedrich Horner, the Swiss ophthalmologist who first described the syndrome in 1869. Several others had previously described cases, but "Horners syndrome" is most prevalent. In France and Italy, Claude Bernard is also eponymized with the condition (Claude Bernard–Horner syndrome, abbreviated CBH). In France, Francois Pourfour du Petit is also credited with describing this syndrome. Children
The most common causes in young children are birth trauma and a type of cancer called neuroblastoma. The cause of about a third of cases in children is unknown.