Can exogenous ochronosis develop after stopping hydroquinone? (Photos)

Exogenous ochronosis is a potential side effect of prolonged use of hydroquinone, particularly at higher concentrations or with long-term use. It is characterized by blue-black pigmentation and can develop even after stopping the treatment. However, diagnosing the exact cause of your symptoms requires careful consideration of several factors.

Here are some possibilities for the darkening and widening of the area near your mouth:

1. **Rebound Hyperpigmentation**: This can happen after stopping hydroquinone, especially if the skin is not protected from the sun. Hydroquinone can make your skin more sensitive to UV radiation, and without adequate sun protection, the treated area can become darker.

2. **Sun Damage**: If you were not using adequate sun protection after discontinuing hydroquinone, UV exposure could have contributed to further darkening of the skin.

3. **Post-Inflammatory Hyperpigmentation (PIH)**: Given that you had a breakout in the area, it's possible that the inflammation from the acne has led to post-inflammatory hyperpigmentation, which can cause darkening of the skin.

4. **Exogenous Ochronosis**: While this is less common and typically associated with prolonged use of hydroquinone over many months or years, it is still a possibility. Ochronosis presents as blue-black pigmentation and often has a "mottled" appearance.

### Recommendations:

1. **Consult a Dermatologist**: A dermatologist can provide a definitive diagnosis and recommend appropriate treatment. They may use tools such as a Wood's lamp examination or a skin biopsy if ochronosis is suspected.

2. **Sun Protection**: Regardless of the cause, using a broad-spectrum sunscreen with an SPF of 30 or higher daily is crucial to prevent further hyperpigmentation.

3. **Alternative Treatments**: There are other topical treatments for hyperpigmentation, such as azelaic acid, kojic acid, vitamin C, or retinoids, which might be safer options under professional guidance.

4. **Gentle Skincare**: Use gentle, non-irritating skincare products to avoid further aggravation of the skin.

In summary, while exogenous ochronosis is a possibility, it is essential to get a professional evaluation to determine the exact cause and appropriate treatment for your skin condition.