Final answer:
The specific percentage of patients with generalized pruritus who have an associated systemic condition cannot be provided without current medical data. However, pruritus can be a symptom of numerous conditions and the prevalence of such systemic conditions could be related to the varied incidence rates of allergies and other diseases worldwide.
Step-by-step explanation:
The question you've asked pertains to the percentage of patients with generalized pruritus (itching) who have an associated systemic condition. Unfortunately, without access to current medical literature, I do not have the exact statistic available. However, generalized pruritus can indeed be a symptom of an underlying systemic condition in a significant number of cases. Conditions that may cause pruritus include but are not limited to renal disease, liver disease, thyroid dysfunction, hematological disorders, and malignancies.
Given the increase in the prevalence of allergies, especially in developed countries, with around 20 percent of people experiencing hay fever or contact dermatitis and about 6 percent having food allergies, it is conceivable that allergies could be related to cases of pruritus. In contrast, allergies and related symptoms like pruritus are less common in poorer nations. The varying prevalence of medical conditions, as mentioned in other statistics, might also contextualize the prevalence of systemic conditions associated with pruritus globally.
However, for a specific percentage related to patients with generalized pruritus, it is advisable to consult the latest medical research or dermatological studies to obtain the most current and accurate data.