The timing depends on wound depth, bacterial load, and immune status. Simple skin infections (redness, pain, warmth) may become noticeable within 24–72 hours. The hallmark lymph node swelling of cat scratch disease typically appears 1–3 weeks after exposure. Rapidly spreading redness, streaking, severe pain, fever, or pus should be evaluated promptly. People with higher risk (e.g., immunosuppression, diabetes) should seek earlier assessment.