Acute hair matting

Author: Dr Ebtisam Elghblawi, Dermatologist, Tripoli, Libya. DermNet New Zealand Editor in Chief: Hon A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand. Copy editor: Maria McGivern. May 2017.

What is acute hair matting?

Acute hair matting is a rare acquired condition that presents as a sudden solid mass of permanent matting of scalp hair on the vertex in otherwise healthy individuals. The process of hair matting is similar to the process of ‘felting’ seen in the wool and textile industries, where adjacent fibres are compacted due to surface scratching and abrasion.

In acute hair matting, the hair twists irregularly and is severely entangled, forming a stiff tightly packed mass of keratin over the head cemented together with dirt and exudates.

Acute hair matting is also called plica neuropathica, plica polonica, and bird’s nest hair.

Plica polonica CM UJ2

Plica polonica 1

1. Creator:Thomas Salmon Creator:Felicità Sartori ( [Public domain], via Wikimedia Commons

Other forms of hair matting

Less extreme forms and deliberate forms of hair matting are known as felted hair, dreadlocks or jata and appear in many cultures, including those of Indian and African peoples (see Hair care practices in women of African descent). These forms of hair matting can be worn for a variety of reasons, including religious or spiritual convictions, ethnic pride and political purposes.

Sartori Plica polonica

Plica polonica2

2. By pracownik Katedry Historii Medycyny Collegium Medicum Uniwersytetu Jagiellońskiego (Own work) [CC BY-SA 3.0 (], via Wikimedia Commons

Who gets acute hair matting?

Acute hair matting is most commonly seen in women with long curly hair, with longitudinal splitting and weathering of the hair, as this type of hair tends to mat easily.

Traditionally, it has been thought that people with ‘hysterical tendencies’ or poor mental health are more prone to acute hair matting.

The term ‘plica polonica’ came from the 19th century Polish tradition of wearing tight fur caps and not washing the hair. This contributed to a muddy, filthy and malodorous compact mass over the head, frequently associated with lice infection and boggy inflammation in the scalp. Another contributing factor was sweating, which moistened the hair enough to allow the head covering to serve as a frictional force that helped create the acute hair matting.

What causes acute hair matting?

Acute hair matting may be due a combination of physical, chemical and behavioural factors. These include:

What are the clinical features of acute hair matting? 

Acute hair matting presents with a stiff prominent and impenetrable mass of matted hair and, in many cases, is associated with a foul smell.

What are the complications of acute hair matting?

The main complication of acute hair matting is bacterial infection, especially impetigo.

How is acute hair matting diagnosed?

Acute hair matting is diagnosed by its appearance. Trichoscopy may be used to detect small tufted knots, hair twisting, nits and lice infestations.

What are the differential diagnoses for acute hair matting?

Some specific hair-styling habits, such as applying sticky substances over the hair or deliberate hair matting — dreadlocks — can be mistaken for acute hair matting.

The main differential diagnoses for acute hair matting are:

What is the treatment for acute hair matting?

The treatment of acute hair matting is usually difficult.

Treatment involves the manual separation of the twisted hairs by using an organic solvent in the early stages of matting, or cutting out the matted hair. It may involve:

Prevention of acute hair matting includes proper hair care measures, such as:

Individuals whose long hair has a tendency to mat should refrain from piling their hair over the crown while washing and backcombing, and avoid rotatory rubbing of hair.

What is the outcome for acute hair matting?

The prognosis of acute hair matting is good, especially if it is treated early.

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