Final answer:
The principles of systemic dermatological therapy involve the use of medications that affect the body as a whole, interacting with the integumentary system to treat skin conditions. Systemic treatments vary and can include oral or injectable medications, and some topical medications like corticosteroids can have systemic effects as well.
Step-by-step explanation:
The principles of systemic dermatological therapy involve treating skin conditions that may require medication which works throughout the body, rather than just topically. One of the key aspects of systemic therapy is understanding how the integumentary system, which includes the skin, hair, and nails, operates and how it interacts with various medications. Systemic treatments can range from oral medications to injectables that aim to alleviate skin conditions from within the body, addressing not only the symptoms but also, at times, the underlying causes.
For instance, hydrocortisone cream, a topical corticosteroid, is used to reduce inflammation and relieve skin irritations by decreasing the secretion of histamine which is responsible for inflammatory responses. While this particular medication is topical, systemic counterparts exist that seek to modulate the body's immune response and are absorbed into the body to exert their effects. Moreover, several medications can achieve systemic effects through selective permeability, entering the bloodstream through the capillaries in the dermis. This same principle allows for the synthesis of vitamin D through skin exposure to UV light, showcasing the complexity and responsiveness of the integumentary system.