Hi, You may be right. The lesions occured on fore head in clusters may be acne vulgaris. In your case it may be infected with bacteria like staphylococci which ultimately developed pustules and after rupture scabs occured. The acne vulgaris is multifactorial disease. There may be precipitating factors like stress,tension, sleeplessness,hormonal imbalance,drugs like steroids,travelling,oily food,sun exposure..etc In your case, sudden appearnce of acne may be stress or tension or sudden deprivation of immunity or some other. Minocycline 50 mg daily for few months with anti inflammatory drug like nimesulde 200 mg twice day for few days may be taken. Apply nadifloxacine cream on the lesions. Cleanse the face with antiseptic face wash. You may feel better after fewvmonths. I hope you got my answer. Thanks. Dr. Ilyas Patel MD