Why Is The Skin Tender To Touch And Red After Taking Mantoux?

My husband received a Mantoux prior to serving part of his work house sentence. He said after the injection it was painful for almost 30 minutes. The test itself was negative but the site is still tender to touch and red. He also got a "really bad flare up" of his psoriasis. I've had many mantouxs and work as an RN but have never heard of this. Is this normal? Only PMH is allergies to PCN and eggs.