What causes streaks on the surface of a 14-year-old's knee joint, and what should be done about it?

White streaks on the surface of the knee joint in 14-year-olds are usually caused by factors such as striae atrophicae, allergic dermatitis, or urticaria. Patients should receive targeted treatment based on the specific underlying cause. Detailed analysis is as follows:

1. Striae Atrophicae

These are typically associated with sudden weight gain, which can lead to tearing of the skin's fibrous layer, resulting in white streaks accompanied by mild itching. Patients should apply topical medications such as tretinoin cream or salicylic acid ointment under medical guidance to improve symptoms.

2. Allergic Dermatitis

In individuals with sensitive constitutions, accidental exposure to allergens may trigger localized allergic reactions, manifesting as swelling or rashes, along with symptoms like itching and warmth at the affected site. Patients should follow medical advice to use calamine lotion or compound acetic acid dexamethasone cream for treatment.

3. Urticaria

This is a common allergic condition that causes raised, pale wheals (hives) on the skin, often accompanied by intense itching. In such cases, patients should take antihistamines such as levocetirizine hydrochloride tablets or loratadine tablets under a doctor’s supervision.

Besides the above common causes, other conditions such as vitiligo, psoriasis, or tinea corporis could also be responsible. Patients should seek timely medical evaluation and treatment to avoid disease progression.