A substance, such as pollen, that causes an allergy. - Though allergens are not harmful themselves, when they are combined with certain antibodies, a reaction (i.e. the allergy) liberates substances that damage body cells and tissues.. A substance, such as pollen, that causes an allergy. [German. : , allergy; see allergy +. , -gen (from French. ; see-gen).]. alâ²lerÂ·genâ²ic (-jÄnâ²Ä­k) adj.
A Honor Society of Nursing (STTI) answered. Prognosis varies depending on the type of motor neuron disease (MND) and the age of onset. Some MNDs, such as Post-polio syndrome (PLS), are not fatal and progress slowly.People with Spinal muscular atrophy (SMA) may appear to be stable for long periods, but improvement should not be expected.ome MNDs, such as Post-polio syndrome (PLS), are not fatal and progress slowly. People with Spinal muscular atrophy (SMA) may appear to be stable for long periods, but improvement should not be expected.
Differential diagnosis can be regarded as implementing aspects of the hypothetico-deductive method, in the sense that the potential presence of candidate diseases or conditions can be viewed as hypotheses that physicians further determine as being true or false.he differential diagnostic procedure may be simplified if a ' pathognomonic ' sign or symptom is found (in which case it is almost certain that the target condition is present) or in the absence of a sine qua non sign or symptom (in which case it is almost certain that the target condition is absent).