Pityriasis conditions may also be included under the collective heading
Seborrhoeic Dermatitis
(e.g. P. Circinata and P. Steatoides etc).
This article is presented for general information only. It is not intended as an aid to self diagnosis. If you are apparently suffering any of the symptoms described below, you should seek professional advice.
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 following conditions prefixed 'Pityriasis...
The conditions described below may in some circumstances associate with systemic diseases including:
Leukemia, Carcinoma (oesophagus or stomach), Malnutrition, Lupus Erythematosus, Tuberculosis, Hepatic and Pulmonary disease.
And other diseases including:
Psoriasis Capitis, Neurodermatitis, Streptococcal Infection, Ringworm (Tinea Capitis, Favus), Impetigo, Ichthyosis, Seborrhoeic Dermatitis (of Scalp)
Some of these diseases are described in Articles of Interest (see title-bar - Site Content)
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The following list describes the types of Pityriasis.
'Dandruff' or Pityriasis Simplex Capitis (PSC) Syn. P. Sicca
'Dandruff' is a popular collective name (non-specific non-technical) signifying a 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) due to the presence of Pityrosporon Ovale. Pruritis may co-exist. It is common to both sexes and shows no affiliation to race or skin colour.
Human skin continually manufactures and sheds cells. Clothing often assists in the shedding. Hairy skin may contain these exfoliated cells which articulate to form scales.
PSC may be an indication of a more serious condition.
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Pityriasis Circinata (Rotunda)
Pityriasis Circinata (syn. Pityriasis Rotunda) is a rare condition. It presents as distinct oval/circular, pink/light brown skin and fine scaly pigmented lesions 0.5 – 2.0cm in diameter. Pruritis and Seborrhoea may co-exist.
A roughly circular boarder will often be present. Lesions tend to affect the scalp, buttocks, torso, face, and lower extremities (feet and ankles).
P. Circinata is not contagious and is not life threatening. It shows no affiliation to race, colour or gender. Lesions tend to become apparent during 20-45yrs. Research in Sardinia demonstrates that the onset tends to become apparent during 3-7yrs. The elderly may also be affected.
P. Circinata may be classified as Idiopathic. Autosomal dominant inheritance is likely.
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Pityriasis Steatoides (PS)
Pityriasis Steatoides presents as crusted skin lesions characteristic of seborrhoea. Exfoliation is more profuse than with normal skin. Odour may exist. The scales have a custard appearance with a waxy/sticky texture. The underlying skin may be inflammatory (pink/red). There may be a visible boarder exhibiting similarities to Pityriasis Circinata.
Sufferers include residents of hot humid climates and those who perspire heavily. Excessive production of sebum aids fungus proliferation.
PS may affect the scalp, also the nose, ears, eyebrows, central chest and back area. PS is non-contagious.
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Pityriasis Rosea (PR)
Pityriasis Rosea presents as a mild exanthema (a disease accompanied by a skin eruption) at any age (predominantly 10-35yrs). Some suggest that the elderly and very young are immune. Hyper/Hypo pigmentation may be present especially in dark skinned persons.
Typically a 1-2cm oval red lesion ("herald" or "mother patch") forms on the chest or back. The centre may have a wrinkled texture and is often salmon pink. Scales may be present. Within a few weeks (2-21 days), numerous smaller oval pink lesions may appear on the torso (often resembling a Christmas tree in shape) the limbs and neck. In rare cases the face is inculcated.
Females are more susceptible to the disease. PR may be confused with ringworm. Diagnosis is assisted by skin biopsy or blood test. Recurrence is rare. PR is not believed to be contagious or symptomatic of internal disease.
Symptoms
Prodromes (early symptoms) may include: tiredness, nausea, fever, joint ache or pain, lymph node swelling and headaches. Pruritis (itching) is often present.
Causes
PR is classified as idiopathic. Viral infection (herpes 6 and 7) is suspected. Some drugs may induce PR e.g. barbiturates, captopril, gold, bismuth, organic methoxypromazine, metronidazole, D-penicillamine, isotretinoin, mercurials, tripelennamine hydrochloride, ketotifen, and salvarsan.
This benign illness is exacerbated by sweating, or bathing in hot water.
Symptoms may last six weeks or more.
Treatments may include:
Soothing creams, anti-pruritics, corticosteroids (in serious cases).
Ultra violet light.
Avoiding causes of heavy perspiration and hot baths.
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Pityriasis Versicolor (PV)
Pityriasis Versicolor is a common non-contagious skin disorder caused by excessive production of Pityrosporum Orbicular (Malassezia Furfur), a yeast present on normal skin. Typically, PV affects the neck or torso; however the whole body may be affected.
In Caucasians, lesions are usually pink or copper coloured. Pruritis and exfoliation may be present. Malassezia Furfur produces a chemical that prevents melanin production - therefore tanning is prevented. It is common in hot humid climates and in persons who perspire heavily. Excessive production of sebum aids fungus proliferation. PV will often be prominent in summer. Recurrence is common. Research suggests that immune deficiencies (e.g. HIV) may assist fungi to spread. The condition is temporary.
Diagnosis
Confusion with psoriasis and ringworm is alleviated by biopsy. PV fluoresces yellow-green under Wood's Light. Treatment
Ketoconazole. Selenium Sulphate. Zinc Pyrithione. Coal Tar shampoos may assist in the management of the condition.
Sunbathing may hide the condition.
Professional diagnosis should always be sought.
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Pityriasis Lichenoides (PL)
Pityriasis Lichenoides is a rare non-contagious skin condition that presents as Pityriasis Lichenoides Chronica (PLC- chronic) and Pityriasis Lichenoides et Varioliformis Acuta (PLEVA or Mucha-Haberman's disease).
PLC and PLEVA may affect either sex at any age. Adolescents and young adult males are more susceptible. Typically, the torso, thighs and arms (inner, upper region) may be affected. The scalp and face are rarely inculcated. P.Lichenoides may last for months or years. Fever may co-exist.
PLC presents as small firm red-brown lesions 3-18mm in diameter. Scales may be present. Pruritis may co-exist. The lesions tend to level over a 2-3 week period, leaving a brown macule which will fade within a few months. The condition may be confused with chicken pox or shingles. PLEVA presents as: pruritic, crusted lesions that may blister. Cicatrices (scar tissue) may occur similar to chickenpox. Mouth ulcers may be present.
Cause
Pityriasis Lichenoides is idiopathic. No specific virus or bacteria has been implicated. Hypersensitivity to a micro-organism may contribute. A skin biopsy may assist diagnosis.
Treatment
Consult a Specialist.
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Pityriasis Alba (PA)
Pityriasis Alba (Latin – white) presents as white or light pink round/oval lesions of approx. 1-4cms). Scales if present are fine and adherent. Examination may reveal lesions with raised edges. Temporary hypo-pigmentation may occur.
PA is a mild benign skin disorder. It may affect anyone but school children with darker skins in tropical countries are most vulnerable. There is no obvious race link. Lesions may worsen during warm weather.
Sites: the face upper arms, neck or shoulder/upper torso.
Most cases resolve within a year.
Greater exfoliation occurs in cold or dry climates.
Cause
PA is classed as idiopathic. Exposure to sunlight may be a factor. No conclusive link to bacterial or viral infections currently exists.
Hypo-pigmentation may be caused by Pityrosporum Ovale (yeast), other idiopathic disorders such as vitiligo, or it may be a reaction to some medication e.g. benzoyl peroxide, retinoic acid and some topical steroids.
Treatment
See your Dermatologist.
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Pityriasis Rubra Pilaris (PRP)
Pityriasis Rubra Pilaris is a chronic papulo-squamous disease (a skin eruption composed of papules and loose scaly lesions), characterised by a reddish/orange patchy rash on the scalp, chest or face, which may extend to other regions. Erythroderma (abnormal redness of the skin), scaling and loss of hair may co-exist.
PRP may be inherited as an autosomal dominant trait or as a sporadic manifestation. The inherited form often onsets from early childhood.
Nail shedding/deterioration may be evident. Both sexes are equally affected. There are no suggested race links. In mild cases PRP will affect the elbows and knees. However it may affect the entire body. PRP may be confused with Psoriasis
Cause
PRP is considered an idiopathic condition. Burns, rashes and infections may trigger the onset.
Biopsy is a positive diagnostic aid.
PRP can be divided into six categories:
Classical adult type
The most common type of PRP. At onset a scaly patch is exhibited on the scalp or upper torso. Further patches may appear within weeks, which tend to cause red lesions at hair follicle sites. Palms and soles thicken and fissures develop Scales on the scalp thicken.
Atypical adult type
Extremely rare showing similarities to the classical adult form which has no recognised progression. Alopecia is often present. The legs may present severe scaling.
Classical juvenile type
Symptoms identical to the classical adult type, the progression is rapid. Some cases follow infection e.g. sore throat. The onset presents within the first two years of life.
Circumscribed juvenile type
Affects the elbows and knees presenting follicular plugs surrounded by reddened skin. Patches may appear on the scalp and body especially in pre-pubertal children. It may not show remission until late teens.
Atypical juvenile type
A hereditary condition. Characterized by prominent hyperkeratosis (formation of excess keratin on the surface of the epidermis) on the soles of the feet linked too poor bone development, and frequent erythema.
HIV associated type
Often presents as pustular acne type lesions, which may appear elongated. Patients tend to show resistance to standard treatments. Anti-retro-viral therapies are known to be effective.
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© 2003 E.J.W.Stevens BSc LTTS
Orthodox Hair-sciences & Hair-specialisms - The Trichological Society
