Is it necessary for dandruff to be medically diagnosed?

Generally, no, but when dandruff becomes severe enough not to respond to self-care measures and over-the-counter medicated shampoos, a consultation with a medical doctor or dermatologist may be helpful. If skin flaking is severe, and affecting other areas of the body, a person may have developed seborrheic dermatitis – severe indications of this condition include pus drainage or fluid and crusty formations which can all be fairly painful and inflamed.

A person with mild dandruff can request the advice of a pharmacist and select over-the-counter products to try before consulting a medical doctor.

What to expect at a medical consultation

At a consultation, a doctor will wish to assess a person’s scalp so as to either diagnose or rule out any other skin-related conditions which can cause similar symptoms of the scalp.

The main skin conditions affecting the scalp that a doctor will keep in mind in order to make a differential diagnosis include:

• Seborrheic dermatitis (SD): Scales may be thicker, greasy and yellow in colour, and the condition may also affect the face, upper torso and back.
• Atopic dermatitis: This condition is characterised by inflammation of the skin causing itchiness and erythema, as well as swollen and cracked skin.
• Impetigo: A skin infection that results in the formation of red and swollen sores. These sores can develop crusts that are yellowish in colour. This condition is brought on by a bacterial infection and is therefore contagious.
• Psoriasis: An accumulation of dead skin cells which form at a quicker rate than is normal, resulting in patches of dry and itchy scales. Psoriatic scaling patches are normally sharply demarcated and inflamed (resulting in redness). Scales also occur in abundance and are silvery white in colour. If psoriasis is suspected, a doctor will also check other areas of the body commonly affected by this skin condition such as the knees and elbows, as well as the folds of the body. Nail changes can also occur in a person with this skin condition and include nail pitting (depressions in the nails), separation of the nail beds and discolouration.
• Allergic contact dermatitis: In this instance, a person may experience severe itching of the scalp as a result of a topical medication (sometimes those that are used to treat severe dandruff or SD) or hair care products. This skin condition may occur along with or as a complication of seborrheic dermatitis. A doctor may recommend an allergy patch test to make a diagnosis.
• Pemphigus foliaceous: Erythema and scaling are common indications of this autoimmune skin disorder. Painful erosion of the skin and crusting may also occur, affecting the scalp and facial area. These can sometimes extend to the chest and back areas as well – in this way this condition can appear to resemble SD.

A physical examination of the scalp is typically how severe dandruff or seborrheic dermatitis will be diagnosed.

To determine the severity of dandruff a doctor will assess a person’s scalp by dividing it up into quadrants. Each scalp quadrant will be assessed under lights and graded accordingly. The doctor will then draw a statistical conclusion comparing the analysis of each quadrant, determining overall severity. He or she will then use the final grade to match up to treatment measures likely to be most effective.

Scalp that is not affected by dandruff will be graded as follows:

Scalp Condition	Severity Classification	Scalp Description	Grade Score of Severity
Dandruff-free scalp	O	Scalp that is healthy and is not affected by dryness or dandruff.	0
Dry scalp	A	Scalp that is affected by a mild or fine dryness and dry hair (lacking in moisture).	1

 A scalp that is affected by dandruff will be classified in the following grades:

Scalp Condition	Severity Classification	Scalp Description	Grade Score of Severity
Mild dandruff	B	Dandruff flakes that are small (or fine) and powder-like occurring in small patches on the scalp and / or hairline.	2
Moderate dandruff	C	Scale-like flakes of dandruff are loosely sticky / attached to the scalp and hair shafts. Small flakes are accompanied by erythema and some itching in localised patches.	3
Severe dandruff	D	Dandruff flakes or scales are larger and more pronounced, as well as crusty. Flakes in various sizes are more widespread on the scalp (and the hairline). Flakes are accompanied by erythema / inflamed skin and severe itching.	4
	E	Dandruff flakes and scales are very large (almost disc-like) and crusty, forming thick clumps on larger portions of the scalp and / or   hairline. Erythema and scalp inflammation, as well as severe itching will also be noted.	5

A doctor may also be looking for signs of the following during a physical examination:

• Acanthosis (thickening of the skin)
• Hyperkeratosis (also results in a thickening of the skin)
• Parakeratosis (an incomplete maturation of epidermal keratinocytes which causes the abnormal retention of nuclei in the stratum corneum)
• Accentuated rete ridges (thin tissue extensions which project into the underlying connective tissues of the skin / scalp and mucous membranes)
• Focal spongiosis (abnormal fluid accumulation within a localised area of the epidermis / scalp)

It is very rare for a skin biopsy to be recommended. A biopsy may be performed should the following be present:

• Hair follicles that are surrounded by mounds of parakeratotic scale, accompanied by redness and itching.
• Widespread scaling (exfoliative erythroderma)

Dandruff does not typically affect children before puberty. Should a child present dandruff-like signs and symptoms a doctor may likely suspect a fungal infection – tinea capitis. Tinea capitis (a ringworm infection of the scalp) is typically rare among adult populations. A doctor may use a stain (usually Periodic Acid Schiff or Gomori Methenamine Silver) to quantify possible numbers of malassezia species on the scalp and make a diagnosis accordingly.

An infant with possible cradle cap can be diagnosed via physical examination.