Hyperseborrhea blocks the end of the follicle causing skin irritation. Moreover, excess sebum gathers on the scalp, not allowing the skin to breath and resulting in itchiness and in the most complex cases also in seborrheic hair loss.
Seborrheic dermatitis results in inflammation and irritation of the skin with the appearance of cutaneous erythema, an itchy sensation (which leads to scratching, further worsening the condition), folliculitis and hair loss or thinning.
Rubbing the skin results in inflammation of the upper part of the hair follicles, pain and hair loss.

Scalp psoriasis, a hereditary condition, leads to skin irritation and the formation of scabs or off-white flakes without itchiness or hair loss.
Ringworm (tinea capitis), a fungal infection, is characterized by the appearance of one or more scaly or red patches, in which broken, dirty hairs are found that look like they are covered in dust, composed of the fungal spores. It is associated with intense itchiness and strong pain on the scalp.
A definitive, scientifically proven correlation does not exist between itchiness and hair loss, nor between itchiness and scalp pain (trichodynia), nor, lastly, between itchiness and greasy hair.

A notable influence on localized scalp itchiness is attributed to both psychological factors (like anxiety, stress and trauma) and external factors (personal hygiene products, food, chemical agents, cosmetic treatments, etc.).
Correcting these errors can solve the problem only in clinical cases in which scalp itchiness is caused by wrong hygiene habits or cosmetics. For other more serious cases, the cause that produces the itchiness must be removed to get rid of it.

According to whether the problem is seborrhea, dermatitis or dandruff, it is advisable to turn to specific trichological treatments which are able to remove the root cause. Useful remedies to reduce itchiness are sulphur based shampoos, camomile shampoo, nettle shampoo and cortisone cream.