Based on your description and the photo, the dark spot under your lip is most consistent with post-inflammatory hyperpigmentation (PIH), which can occur after an inflammatory lesion, rash, or blistering episode — especially in Fitzpatrick type IV skin. PIH in this area can be particularly persistent due to repeated movement, saliva exposure, and friction. Given that you have already tried pico laser twice without improvement and are using tretinoin 0.05% and hydroquinone 4%, here are important considerations: Treatment Duration & Patience PIH can take several months to fade, especially in deeper pigmentation or in higher Fitzpatrick types. Hydroquinone is usually prescribed in cycles (e.g., 3–4 months on, followed by a break) to avoid resistance or ochronosis. Adjunctive Topical Therapies Consider adding azelaic acid 15–20%, kojic acid, or cysteamine cream as alternate or combination therapies. Niacinamide can also help by reducing melanin transfer to skin cells. Procedural Caution Aggressive lasers (including pico) can sometimes worsen PIH in darker skin types. Gentle, low-fluence settings or other modalities such as microneedling or chemical peels with glycolic/lactic acid may be safer. Sun Protection Strict daily sunscreen use (SPF 50+, broad-spectrum) is critical, even indoors, as visible light can contribute to pigmentation. Underlying Trigger Since this followed a cold sore-like rash, consider evaluation for recurrent herpes simplex virus, as recurrence could lead to repeated pigmentation changes. Preventing new episodes is as important as treating the spot. In summary, the persistence is not unusual for PIH in this location and skin type. Gradual improvement can occur with consistent topical therapy, strict photoprotection, and careful selection of in-office procedures.