Acne or Allergies?

I am 35 year old, I have had problems with my face breaking out since I got pregnant with my son at 21.  But now I'm wondering if it's not an allergy problem of some sort.  When I get a pimple, if I scratch it or pop it, the skins turns to leather and is real tough and itches beyond belief.  I'm not sure what is going on but I mainly get them around my hairline on my entire head and around my mouth.   I have recently started having problems with them on my back doing the same thing.  They almost look as if they've been burnt.  I'm just wondering what in the world is going on.  

[loiloi]

Hi. Acne is caused by a sensitivity to the effects of androgens (male hormones such as testosterone) which stimulate the sebaceous glands. Bacteria on the skin feeds off this oil, blocking the pores and leading to spots. The standard treatment for acne is a course of oral antibiotics such as Oxytetracycline 250mg twice daily and a topical retinoid gel such as Differin. Female acne patients may also benefit from taking an anti-androgen contraceptive pill such as Yasmin and/or an anti-androgen medicine such as Spironolactone.
Your GP will easily be able to distinguish acne from allergies.
Best Wishes, Eloise.