Final answer:
Clinical pruritus refers to severe itching of the skin often associated with conditions like eczema, contact dermatitis, and psoriasis. Summation effect in neurophysiology explains how minor changes in membrane voltage can cumulatively lead to reaching the threshold for a response. Treatment and diagnosis for related conditions involve maintaining skin moisture and performing allergy testing.
Step-by-step explanation:
Clinical Pruritus and Summation Effect
Clinical pruritus refers to the medical term for severe itching of the skin, a common symptom in various conditions such as eczema, contact dermatitis, and psoriasis. It can result from different causes including allergies, infections, or underlying systemic diseases. The summation effect is a term in neurophysiology that describes the cumulative change in postsynaptic potentials when multiple stimuli are combined over time or across different parts of the membrane, potentially reaching the threshold to trigger a response, such as an itch sensation.
For instance, in the case of eczema, an allergic reaction can manifest as dry, itchy patches of skin that resemble rashes. This condition can sometimes be related to antibodies against dust mites present in the patient's blood, although the direct link has not been definitively proven. Treatment for such symptoms often includes moisturizers, corticosteroid creams, and immunosuppressants to manage the itching and inflammation.
Diagnosis of underlying hypersensitivities, like in the case of type I hypersensitivities, can include measuring serum IgE levels and conducting skin tests such as the puncture skin test (PPST) or intradermal test. These tests look for a wheal-flare reaction to the introduced allergens which, if present, indicates a type I hypersensitivity reaction. The greater the wheal and flare, the more sensitive the patient is to the allergen.