Assessment: Given your description of acne with red blister-like pimples on your forehead, it's recommended to seek medical evaluation to determine the cause and appropriate treatment.

Treatment Consideration: Over-the-counter topical treatments containing benzoyl peroxide or salicylic acid may be initially tried. If no improvement occurs or if the acne is severe, consult a dermatologist for potential prescription treatments.

Medication Note: If considering stronger treatments like Isotretinoin, professional guidance and prescription are essential due to potential side effects.