Download Optimal management of seborrhoeic dermatitis

Derm Oct-AH/NH/SON*
9/10/06
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Dermatology
Optimal management of
seborrhoeic dermatitis
Approximately 3%-5% of the
population suffers from
seborrhoeic dermatitis which is a
chronic, relapsing condition,
writes Bernadette O’Leary
Figure 1. Red, scaly rash of
seborrhoeic dermatitis in a
typical facial distribution
Table 1
DERMATITIS MEANS SKIN INFLAMMATION and seborrhoea
means sebum. Seborrhoeic dermatitis (SD), as the name
hints, means inflammation of the sebum or oily-rich areas
of the skin, that is, areas rich in sebaceous glands. But as
sebum isn’t known to cause inflammation, several other theories have been postulated for the aetiology of SD such as
hormonal levels, CNS causes and the overgrowth of a yeast.
The possible hormonal links are raised because of the
appearance of the condition in infancy (secondary to maternal hormones) and also because of its post-puberty
appearance (higher androgen levels starting to circulate).
A link with the CNS and some possible neurogenic deficiency has been proposed because of its association with
Parkinson’s disease and other neurologic disorders including post CVA, epilepsy and facial nerve palsy. A more causal
link seems to exist between SD and the proliferation of the
Malassezia species, ie. Malassezia furfur and Malassezia
ovalis because of the ability to isolate it in patients with SD
and by the therapeutic response of seborrhoeic dermatitis
to antifungal agents.
This species lives on the sebaceous gland-rich areas
(head, upper back and chest) of most people’s skin, needing oil to survive. Its overgrowth in patients with SD is felt
to cause irritation of the skin, either directly or through the
secretion of a toxin triggering the inflammatory cascade
causing hyperproliferation, scaling and erythema of the skin.
It is not contagious and is not the same yeast that is present
in food products, so dietary exclusion of yeast foods hasn’t
been found to be of help.
Classification
Males are affected more than females in all age groups.
SD is seen frequently in patients with Parkinson’s disease,
perhaps due to neurotransmitter abnormalities resulting in
increased sebum production. Levodopa decreases sebum
production, so SD usually improves in these patients when
commenced on it.
HIV may first present in patients with a generalised SD
rash. This is felt to be secondary to their reduced immunity,
Differential diagnosis
Scalp
Psoriasis
Atopic eczema
Contact allergic dermatitis
Pityriasis amantacia
Tinea capitis
Flexures
Psoriasis
Intertrigo
Candidiasis
Erythrasma
Ear
Psoriasis
Atopic eczema
Sebo-psoriasis
Contact dermatitis
Face
Rosacea
Psoriasis
Eczema
Impetigo
Body
Pityriasis rosea
Pityriasis versicolor
Psoriasis
resulting in overgrowth of the yeast. Many patients give a
positive family history of dandruff, SD or psoriasis even
though it is not felt to be hereditary. Exacerbations usually
occur in the winter as UV light inhibits the malassezia
species. Drugs (eg. cimetidine and neuroleptics) and stress
can also cause exacerbations.
Distribution
Seborrhoeic dermatitis can affect the scalp; face; nasolabial
folds, eyebrows, external ears, eye-lashes, glabella, beard
area, axillae, umbilicus, groin and inframammary area. It can
frequently become apparent when men grow moustaches or
beards and disappear once the facial hair is removed.
FORUM October 2006 55
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Dermatology
Table 2
Treatment of adult SD
• Frequent washing
Anti-fungals
• 2% Ketoconazole shampoo/cream (Nizoral)
Thrice wkly
• Selenium sulphide shampoo (Selsun)
Twice wkly
• Zinc pyrithione shampoo (Head and Shoulders)
Thrice wkly
• Tar shampoos (capasal, T Gel, Exorex)
Thrice wkly
Anti-Inflammatory (immunomodulatory) agents
• Steroid shampoo, eg. Bettamouse
Twice wkly
• Topical steroids with antifungal ointments/creams eg. Daktacort, Canesten HC
Daily
• Lithium succinate ointment (Efalith)
Daily
• Topical calcineurin inhibitors -eg. tacrolimus ointment (Protopic)
Daily
Keralolytics
• 3%-5% salicylic acid shampoo
Twice wkly
• Tar with anti-fungal shampoo
Thrice wkly
• Zinc pyrithione shampoo-also antifungal
Twice wkly
• Warm olive oil washed out 4 hrs later with tar shampoo
Thrice wkly
Anti-androgens (females)
• Dianette, Yasmin, Spironolactone
Daily
Others treatment for refractory Ds
• Roaccutane
• Oral ketoconazole
200mg od x 14 days
• Oral itraconazole
100mg od < 21 days
• UVB therapy
Wkly
Alternative medication
• Tea tree oil shampoo
Daily
• Vinegar
Daily
Clinical appearance
For mild scalp scaling, the term ‘dandruff’ is used. When
the inflammatory cascade increases with scaling plus erythema arising in certain locations in the body, the term
seborrhoeic dermatitis is used. Adult SD usually commences
with a mild greasy scaling of the scalp, with scaling and erythema of the nasolabial folds or post auricular skin. In
Afro-Caribbean skin, the diagnosis is more difficult. The
scaling is prominent but the erythema may be masked by
the darker skin. Sometimes, post inflammatory hypopigmentation is seen after treating these patients. Two types of
SD may appear on the chest – a common petaloid type –
named after its resemblance to flower petals, and a rarer
pityriasiform type which resembles pityriasis rosea.
For some patients, chronic otitis externa may be the only
manifestation. However, another possible manifestation is
blepharitis with eyelid crusts and scale, sometimes resulting in meibomian gland occlusion and abscess formation.
Seborrhoeic dermatitis is usually diagnosed clinically by
its appearance and distribution but if doubt arises a skin
biopsy may distinguish it from similar disorders, eg. SD on
the scalp margin can be difficult to distinguish with psoriasis, hence the term applied – ‘sebopsoriasis’.
Good hygiene
For the patient who normally shampoos just once a week,
increasing this to daily or alternative day shampooing may
be enough to clear mild dandruff and erythema. Similarly
for the face, daily cleansing with a mild soap and water may
be enough if they were not doing this previously. It is impor56 FORUM October 2006
tant to note though that skin affected by SD is more sensitive than normal skin so if the mild soap irritates, a
fragrance-free cleanser, eg. Emulave, or Alveeno range of
cleansers may be tried.
If the skin is extremely dry and sensitive, water alone
should be used. To aid in deciding whether ingredients in
cleansers, cosmetics or moisturisers may be potentially irritating, check www.zerozits.com/Articles/acnedetect.htm – this
webpage lists skin-irritating ingredients in moisturisers
(scroll down the page for the list). Medicated cream or ointment can replace the need for a moisturiser.
For men, electric razors can provide a less irritating shave
than razor blades. If a wet shave is preferred, shaving products need to be chosen very carefully as they may irritate the
skin. In general, shaving gels or oils seem to be less irritating than shaving creams.
If regular washing isn’t clearing the SD, then the addition
of an antifungal agent may help.
Anti-fungal treatment
Using 2% ketoconazole kills the Malassezia yeast. It is
also more cosmetically acceptable than tar shampoos, which
can have a distasteful smell. Selenium sulphide has been
found to have similar efficacy as 2% ketoconazole when
compared but can cause scalp burning, lightening of hair
colour and an orange staining of the scalp.1
In 1994 Faegemann found the use of topical ketoconazole to be superior over other imidazoles at decreasing
Malassezia.2 Two separate studies have shown 2% ketoconazole cream to be as effective as steroid creams four
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Dermatology
Table 3
Treatment of infantile SD
Scalp
• Olive oil rubbed into the scalp followed by brushing
with soft brush
• Frequent shampooing with 1:10 dilution Johnson’s
baby shampoo
• 0.5%-1% hydrocortisone cream
• 2nd line – 2% ketoconazole
Body
• Daily bath with oil/emulsifying ointment
• Emollients
• 1% hydrocortisone
• 2% ketoconazole cream bd < 2 weeks
weeks post-treatment and often resulting in more prolonged
remissions without the risk of skin atrophy/telangiectasia.3,4
However, skin creams may need to be used initially with
ketoconazole creams as approximately 10% of people report
skin irritation with it. In 1999 Bulmer et al compared 2%
ketoconazole with zinc pyrithione (Head and Shoulders) and
found ketoconazole to be 100 times more effective at clearing SD.5 Also, the recurrence rate was significantly lower
with ketoconazole.
Ketoconazole can be drying on the hair so a conditioner
may be used after it has been left on the scalp for three to
five minutes before rinsing off. Due to the thick hair type of
most Afro-Caribbeans, leave the 2% ketoconazole on the
scalp (not hair) for 15-20 minutes.
Anti-inflamatory treatment
Steroid treatments are better not used long-term because
of their side-effects and patient dependence. Oral steroids
are occasionally used short-term in severe attacks or resistant cases. Topical tacrolimus (Protopic) ointment has
fungicidal and anti-inflammatory properties without the risk
of cutaneous atropy. Clinical improvement occurs after one
week of use. Sun-screens must be used with it and the skin
must be devoid of infection. Long-term studies are awaited
on this product.
An alternative anti-inflammatory treatment to steroids is
Efalith. This cream contains lithium succinate and zinc.
However, it is quite expensive. It is usually reserved for
second-line treatment as it can cause skin irritation.
Descaling agents (keratolytics)
Removing scale first will allow topical treatment to act
better on the skin.
Refractory disease
Roaccutane may be used to decrease sebaceous gland
activity and thus reduce sebum production. It also has antiinflammatory properties. It is used in resistant cases. Lower
doses to that used to treat acne are used and also a quicker
response is seen, usually by four weeks. The dose is
0.1mg/kg-0.3mg/kg as opposed to 0.5mg/kg-1mg/kg used
in acne. Contraception is essential for one month before its
use and for three months post its discontinuation.
Alternative medicine
Tea tree oil is an essential oil and found to have fungicide
activity, especially against Malassezia species.6 The therapy
appears to have some effect and is well tolerated when used
daily as a 5% shampoo.6
Vinegar
Some anecdotal evidence suggests that vinegar applied
topically can improve SD. It is believed to act as an antifungal agent via its acidic properties thus hindering the yeast’s
ability to colonise the skin. Supposedly, the Malassezia
species doesn’t thrive well in acidic environments. Antiandrogens, eg. cyproterone acetate (Dianette), drospirone
(Yasmin), and spironolactone may be useful in women when
oily skin is believed to contribute to SD.
Infantile SD
Rare and different to adult SD, this usually occurs from
three months onwards, peaks at six months and is gone by
one year. It usually presents with thick, yellow, greasy scales
adherent to the scalp. The groins may also become affected
with erythema and scale which involves the flexures. The
axillae may also be similarly affected. In severe cases the
entire body may be affected but this is uncommon in
healthy children. Treatment options are outlined in Table 3.
Those infants with generalised SD should be evaluated for
immunodeficiency as immunocompromised children can get
this. They may also have concomitant diarrhoea and failure
to thrive (Leiner’s syndrome).
Bernadette O’Leary is in practice in Co Waterford
References on request