Can I use Cortizone 10 - Feminine Itch on my labia minora?

I've been having one hell of a time with dry skin lately. Psoriasis runs in my family (as well as eczema) and it's done a number on my entire body this month; it's now spread to my vulva and I'm guessing my labia minora as well. I was finally able to buy Lanolin for my poor cracked, weepy nipples and as I was shopping, I saw feminine itch Cortizone 10 near the feminine washes. 
So my question is, is it safe to use on my labia minora? It says "for external use only", but am I to assume that that just means that I can't insert it into my vagina (not something I'd do anything), or does that include the labia minora as well?