Dandruff
Dandruff does not usually need to be formally diagnosed because its symptoms are obvious. The characteristic dry, white flakes on your scalp or in your hair are typical of the condition.
Seborrhoeic dermatitis
See your GP if you think you may have seborrhoeic dermatitis. They can diagnose the condition by looking at the red rash on your skin. Tests are not usually required.
Ruling out other skin conditions
To confirm a diagnosis of seborrhoeic dermatitis, your GP will examine the redness and colour of the scaling on your scalp.
This will enable your GP to rule out a different skin condition called psoriasis, which causes red, flaky, crusty patches of skin and silvery scales and has similar symptoms to seborrhoeic dermatitis.
If your GP thinks that a fungal infection may be present in your scalp (scalp ringworm), a skin sample may be taken and sent away to a laboratory for testing.
