Pityriasis – Oily Dandruff By Professor Barry Stevens

Pityriasis is a genus of non-pathogenic yeast-like fungi which produce fine spores but no mycelium. It proliferates in “Dandruff ‘and ‘Seborrhoeic Dermatitis’ and in the diseases/ conditions discussed herein – prefixed Pityriasis

Seborrhoea may be defined thus: ‘excess sebum for a specific individuals age and sex’.

Pityriasis can be a chronic inflammatory papulo-squamous disorder patterned on the sebum-rich areas of the scalp, face, and trunk. It presents as areas of erythematous skin covered by large yellow greasy scales. Severity varies from mild pityriasis simplex capitis (‘dandruff’) to exfoliative erythroderma. This paper seeks to mention the pityriasis conditions which may respond to trichological therapy. Other manifestations requiring dermatological advice are also mentioned herein.

Etiology

The aetiology of seborrhoeic dermatitis remains uncertain, but evidence points to genetic factors. At birth sebaceous glands are tiny and inactive but sustained by maternal androgens. As puberty approaches androgen levels rise and sebaceous glands enlarge to commence sebum production. Sebum production is initially similar in adolescents (either gender), until after the 16th year from which time the male’s production rises and remains higher (subject to the presence of testicular androgen) until advanced age. Female levels of sebum reduce with the presence of oestrogen, except during pregnancy. At puberty and beyond sebum gains higher levels of cholesterol and lipids. Cholesterol is a sterol (steroid + alcohol). It plays a central role in many biochemical processes. Lipids are organic compounds (containing hydrocarbons) found in cell membranes of all body tissues. They may be used for energy storage, as structural components of cell membranes, others are important hormones or contain essential fatty acids. Because they consist mainly of carbon, they are soluble in ether and chloroform but relatively insoluble in water. Squalene (a lipid) – is a key intermediate in the biosynthesis of cholesterol and precursor to the whole family of steroids derived from it. At puberty cholesterol and squalene levels dramatically increase in the sebum. Seborrhoeic dermatitis is a worldwide disease, however opinions exist as to its relativity to racial and climatic factors. Seborrhoeic dermatitis is a form of pityriasis as it relates to the activities of the yeast Pityrosporum of Malassezia syn’s: malassez furfur, pityrosporum ovale, bottle bacilli. Dandruff (Pityriasis simplex capitis) is the mildest form of seborrhoeic dermatitis.

Conditions prefixed Pityriasis which involve scalp crusting or exfoliative activity may be injudiciously labelled innocuous dandruff, but may be early symptoms of other diseases or disorders requiring specialist treatment – including: - Psoriasis - Neurodermatitis - Streptococcal - Ringworm - Impetigo - Ichthyosis.

Where doubt exists, early advice should be sought.

Types of Pityriasis

Pityriasis Simplex Capitis (PSC). Syns: P. Sicca, Dandruff

‘Dandruff’ a popular collective non-specific, non-technical name signifying a mild scaly flaking scalp condition. In a simple context this will allude to Pityriasis Simplex Capitis (syn. pityriasis sicca) – a non-inflammatory scalp condition which presents as exfoliation of the Stratum Corneum (outer layer of epidermal cells) with Pityrosporon Ovale (bottle bacilli) present. Pruritis may co-exist. It is common to either gender or shows no affiliation to skin colour. Human skin continually manufactures and sheds cells. Clothing assists in the shedding of body cells. Hairy skin may retain these exfoliated cells for longer which articulate to form scales. PSC may be an indication of a more serious condition. This condition is frequently observed photo is considered unnecessary

It seems to originate from a moist eczematous exudate which hardens into a thick asbestos like crust which is adherent to the scalp and grows up local hair shafts. Occasionally blood is drawn where crusts are torn from the scalp. Its silvery grey / white asbestos like appearance is due to its composition which includes hyperkeratosis and follicular keratosis. As the scale is removed, areas of baldness which may or may not support future hair growth are revealed.

Treatment

Coal tar and salicylic acid as a keratolytic to soften the crust and enable its removal followed by mild topical steroids where indicated. Where psoriasis is a suspected complication, regular treatment may be needed.

ED’s Note: There are coal tar shampoos easily available on the open market at pharmacists without prescription. When you do identify these and other conditions you see here in the Health Blog, please refer you client to a GP also.

The idea behind me putting the professors’ articles in barbershop is so we can learn about the common hair and scalp issues we see every day as barbers and give comfort to our clients because we know a little about them and the treatment for them.

@hairscientists.org

Professor Barry Stevens is one of the world’s foremost experts in Trichology. He heads the Trichological Society in London, and his papers are internationally recognised as a leading source of accurate information on scalp and hair disorders by Doctors and Trichologists alike. He has been a consultant to the BBC, The Thermal Hair Appliance Industry, Unilever Hair Cosmetics and has been awarded for “Outstanding Services to Hair Sciences – Worldwide”