exercise, hot showers, stress, or spicy food.
Delayed pressure urticaria: Shoulder-straps, tool handles, or sitting on hard surfaces can cause deep, painful swelling hours after pressure.
Solar urticaria: Sunlight (or some indoor lights) can trigger rapid wealing.
Aquagenic urticaria (water-induced) and vibratory urticaria (power tools, cycling on cobbles, even vigorous toweling) are rare but real.
What to do: Identify and minimize the stimulus (looser clothing, lukewarm showers, sun protection, avoid cold-water immersion). A daily non-sedating antihistamine can reduce reactivity; specialist care is important for cold, solar, aquagenic, or vibratory forms.
