L20-L30: Dermatitis and eczema
L21: Seborrhoeic dermatitis
Seborrheic dermatitis, falling under the L21 classification in the ICD-10 WHO 2016, refers to a chronic and typically mild form of eczema that often affects areas rich in oil glands such as the scalp, face, and torso. It presents itself through red, itchy skin covered with yellowish or white crusty scales. The exact cause of this skin disorder is unclear, yet a mixture of genetic and environmental factors are believed to play a role. The condition is often linked to the overproduction of skin oil and irritation from a common yeast called malassezia that live on the skin. Progression can vary from person to person, with some patients experiencing modest itching and discomfort, while others might see significant skin inflaming and flaking, possibly impacting their quality of life. Seborrheic dermatitis is not contagious and it does not directly affect other systems in the body.
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The information provided on this page is for general educational purposes only. It is not intended for self-diagnosis and does not replace professional medical advice. Always consult your doctor or a qualified healthcare provider with any questions or concerns about your health.
If you see an ICD diagnosis code (e.g., on a medical report), be aware that doctors may also include additional indicators to express diagnostic certainty. Only a healthcare professional can interpret these codes accurately in the context of your individual case.
For a complete understanding of your condition and what the diagnosis means for you, please speak directly with your doctor.