The Integumentary, Skeletal and Muscular Systems
Psoriasis is a chronic skin disease in which afflicted individuals develop red patches with a scale-like appearance. The cause of psoriasis is a relatively simple one, but it is difficult to treat. The epidermal cells of an individual with psoriasis are dividing 5-10 times more frequently than they should be! This accounts for the excessive accumulation of cells that leads to the symptoms, as they cannot be sloughed off quickly enough to prevent buildup.
What type of drugs might be effective in sever cases of psoriasis?
|A||Collagen creams designed to moisturize the skin.|
|B||Antibiotics that can kill the bacteria responsible for the problem.|
|C||Anitcancer drugs that systemically inhibit mitosis.|
|D|| Drugs that inhibit the formation of sebum, and have also been used to effectively treat acne.|
Since the problem here is excess cell division (which must be by mitosis), anti-cancer drugs that inhibit cell division should be effective (although there are side effects). While collagen is an important component of the dermis, it has nothing to do with psoriasis or the epidermis (choice A). Choice B would only be valid in the case of a bacterial infection, and none exists in this case. Sebum-inhibiting drugs do work against acne, but again, this is due to bacterial infection and is not applicable to psoriasis (choice D).