The Good: Pyrethrins, for the most part, do seem to be relatively safe for most pets, though dosage is still the key. Many on-line sites list pyrethrins as being safe for cats, and as far as we can tell, used judiciously, they are not too much more toxic for cats than they are for dogs.
Yes: Razor bumps will usually go away when you stop shaving. There are a few things you can do to prevent them in the future. Shave in the shower so the heat can soften the hair, and use a shaving gel. Always use a brand new razor, and shave in the direction that your hair grows. Moisturize after shaving.
They also itch quite a bit. Answer. Mosquito bites (or those of any other insects) can be incredibly irritating, both for cosmetic reasons as well as discomfort associated with itching and scratching. Unfortunately, there isn't a good way to expedite the healing process. As you know, the 'bumps' associated with insect bites will go away after a few days, but unfortunately time is the process that helps in the most. In the meantime there are several strategies you can use to help minimize any complications.