I'm sorry to hear about the redness on your lower lip. A red lower lip while the upper lip appears normal can be due to several reasons, including irritation, inflammation, or a localized skin condition. Sometimes, topical treatments or environmental factors can cause such changes.

For example, if you are using a medication like Tacroz Ointment, which contains tacrolimus and is used to treat skin conditions such as eczema, it can sometimes cause side effects like redness, itching, or burning in the treated area. This might explain why only your lower lip is red if the ointment was applied there.

Here are a few possible causes for your symptom:

• Localized irritation or allergic reaction
• Contact dermatitis from lip products or environmental exposure
• Inflammatory skin conditions like eczema or cheilitis
• Side effects from topical medications

It is important to avoid further irritation, keep the area clean, and avoid applying any new products without medical advice.

Recommendation: Please consult a dermatologist (skin specialist) to evaluate your lip condition properly. They can provide an accurate diagnosis and recommend appropriate treatment based on a physical examination. If you experience worsening symptoms such as pain, swelling, or spreading redness, seek medical attention promptly.To narrow down potential causes, we will need some more information.Please tell me your age and gender.