Lichen simplex

Question 1

Definition of lichen simplex

Answer 1

. Underlying dermatoses, i.e. atopic dermatitis, allergic
contact dermatitis, superficial fungal (tinea and
candidiasis) infections.
. Systemic conditions causing pruritus, i.e. renal failure,
obstructive biliary disease (primary biliary cirrhosis
and primary sclerosing cholangitis), Hodgkin’s lymphoma, hyper- or hypothyroidism and polycythaemia rubra vera.
. Environmental factors: heat, sweat, rubbing of clothing
and other irritants such as harsh skincare products.
. Psychiatric disorders: anxiety, depression, obsessivecompulsive disorder and dissociative experiences are often associated with the condition. Emotional tensions in predisposed people (i.e. those with an underlying predisposition for atopic dermatitis, asthma
and allergic rhinitis) can induce itch and thus begin
the chronic itch-scratch cycle

Question 2

Symptoms of lichen simplex

Answer 2

. Vulval itch
. Soreness
- Erythema and swelling with thickening
- Non specific inflammation on labia majora, mons pubis and inner thighs

Question 3

Signs of lichen simplex

Answer 3

. Lichenification, i.e. thickened, slightly scaly, pale or
earthy-coloured skin with accentuated markings, maybe more marked on the side opposite the dominant
hand.
. Erosions and fissuring.
. Excoriations as a result of scratching may be seen.
. The pubic hair is often lost in the area of scratching.

Question 4

Complications of lichen simplex

Answer 4

Secondary infections

Question 5

Diagnosis of lichen simplex

Answer 5

. Clinical presentation. Psoriasis of the vulva is usually less itchy and lesions are bright red, often glazed and well demarcated and frequently involves natal cleft.
. History including mental state examination where
indicated.
. General examination of the skin to look for other
signs of psoriasis or lichen simplex elsewhere.

Question 6

Investigations for lichen simplex

Answer 6

. Screening for infection (e.g. Staphylococcus aureus,
Candida albicans).
. Dermatological referral for consideration of patch
testing
. Ferritin
. Biopsy

Question 7

Treatment of lichen simplex

Answer 7

. Avoidance of precipitating factor.
. Use of emollient soap (some people may have a reaction to aqueous cream when it is used as an emollient. For this reason, it is recommended only as a
soap substitute and not an emollient).
. Topical corticosteroid – potent topical steroids are
required when treating lichenified areas, e.g. betamethasone or clobetasol for limited periods. A combined preparation containing antifungal and/or
antibiotic may be required if secondary infection
was suspected. Apply once or twice daily.
. A mildly anxiolytic antihistamine such as hydroxyzine
or doxepin at night is helpful.
. The symptoms of pruritus often respond fairly
quickly to a topical steroid but, unless the lichenifi-
cation resolves, the itch-scratch cycle will remain and
the symptoms will recur. A graduated reduction in
the frequency of application of the topical steroid is
helpful, over about 3–4 months.
. Cognitive behavioural therapy maybe helpful if there
are co-existing mental health issues.