It is quite common to develop these tiny bumps after stopping oral doxycycline. This is likely pityrosporum folliculitis (often called fungal acne) rather than a regular acne recurrence. Prolonged antibiotic use can suppress skin bacteria, allowing natural skin yeast to overgrow, especially on the forehead and arms. Do not worry, as this is very treatable and not a dangerous reaction. I recommend seeing a dermatologist for an accurate diagnosis. If it is fungal, they may recommend a topical antifungal like ketoconazole. If it is a standard acne rebound, topical treatments like benzoyl peroxide or retinoids can help manage it effectively.