Detailed answer

Blackheads, also known as open comedones, are caused by the accumulation of excess sebum and dead skin cells, which clog the hair follicles. While makeup products can contribute to this process by clogging pores, blackheads themselves are not indicative of an allergic reaction. Allergic reactions to makeup products typically manifest as redness, itching, swelling, or even hives. If you suspect an allergic reaction to your makeup, it's important to discontinue use and consult with a dermatologist for proper diagnosis and treatment. However, if you are experiencing persistent blackheads, it is advisable to examine your skincare routine, including your facial cleansing habits and the types of makeup products you use, to ensure proper pore maintenance and prevention of clogged pores.