Cannabis sativa has known anti inflammatory properties. In Dermatology it has had several studies that suggest it may be beneficial for psoriasis, lupus, itching, pain, acne, herpes, dermatitis, systemic sclerosis, wound healing and skin cancer treatment. There are studies that have demonstrated a decrease in inflammation, redness and oiliness of the skin.
There is a lot of research that still needs to be explored to better understand the role and effectiveness of Cannabis sativa seed oil. Overall, most skin care products that include this ingredient appear to focus on its emollient or hydrating qualities. Its anti inflammatory effects suggest it would be beneficial for itching and inflammation. For anti-aging it is likely simply hydrating the skin as opposed to actively treating or preventing wrinkles.
Overall, in practice I cannot say that the patients I have that have tried specifically for inflammation, itching or chronic rashes have seen much benefit. This is not necessarily due to lack of effective potential but also because of how poorly its use is understood.
It also has the potential to cause allergic reactions or hives in those allergic or sensitive to it. There is a lot more research that needs to be done as some studies have even suggested that it is both anti cancer and cancer causing in some cases. This paradox may simply be a dose related concern which only further supports the need for more research to understand how best to recommend this product!