Atopic dermatitis (AD), popularly known as eczema, is a common and chronic
inflammatory skin disease that has seen a rapid rise over the last few
years. Industrialization, urbanization and the associated lifestyle
has propelled its rise.
This disease that is closely associated with other atopic diseases like
asthma and allergic rhinitis, affects more women than men. Moreover, it
relapses with age with an estimated 40% of AD cases re-occurring even
after attaining adulthood. Its primary causes could be associated with
heredity, environmental interactions, skin barrier disorders or immunological
reactions.
The management and treatment of AD involves the following steps:
- Identification of the triggers (allergens) and avoiding them.
- Restoring
the skin barrier functions with standard treatments of eczema such
as the use of emollients combined with topical corticosteroids,
wet dressings, antibiotics for infections and antihistamines.
- In
acute cases where other treatments fail, systemic therapies are often
implemented.
- Stress management and patient counseling is also an
integral part of therapy.
Types of systemic therapy for atopic dermatitis
Though they come with mixed results and side effects, there are varieties
of systemic therapies for the treatment of atopic dermatitis. They have
been extensively researched and the most prevalent are:
- Oral antihistamines
- Oral steroids
- Systemic immunomodulators
- Phototherapy
- Antimicrobials
Oral antihistamines
There are two of its kind - sedating and non-sedating - that are used
for the treatment of atopic dermatitis. They have been found to be selectively
effective in the treatment of eczema. On one hand, they have not proven
to be successful in reducing itchiness (pruritus) in most cases of atopic
dermatitis. On the other hand, they have proved effective on patients,
who suffer from atopic dermatitis-related sleep disorders (secondary to
pruritus, dermatographism, or allergic rhinitis), dermatographism, urticaria,
or allergic rhinitis.
Systemic steroids
They are best used on a short-term basis in case of acute atopic dermatitis.
However, they are associated with serious side effects and a rebound flare
after discontinuing usage. See our page on corticosteroid treatments for
eczema for more details.
Immunomodulators
Immunomodulators are generally used in severe and unmanageable atopic
dermatitis cases. However, the patient must be kept under close observation
to monitor side effects. Moreover, they should be used for a short span
to minimize side effects. The various immunomodulators and their functions
are:
- Cyclosporine works speedily in about 2 weeks and has proved successful
in the treatment of irrepressible AD. Renal toxicity, hypertension,
nausea, and abdominal pain are some of its possible side effects. It
should be
used for a short span and the condition may revert after the drug
is discontinued. Its adult and pediatric prescription is 3 to 5 mg/kg
daily.
- Azathioprine is administered in case of unmanageable atopic dermatitis.
It is an anti-inflammatory and antiproliferative drug, which is
slow in its activity taking about 4 to 6 weeks to show results. Its
contraindications
(cases when the drug should not be used) are bone marrow suppression,
hepatotoxicity, hypersensitivity reactions, pancreatitis, squamous
cell
carcinoma of the skin, and non-Hodgkins lymphoma. Its adult and
pediatric prescription is 2.5 mg/kg daily.
- Myclophenolate mofetil is
prescribed in an adult dose of 2 g daily for the treatment of AD.
Its side effects include bone marrow suppression
though this can be minimized with its short-term usage.
Ultraviolet (UV) light therapy
Ultraviolet (UV) light therapy or simply phototherapy works as an anti-inflammatory
agent on the cells of the immunity system of the body, thus proving its
worth in the treatment of complex atopic dermatitis. It works well and
is popular with patients. The various types of UV therapy are:
- Psoralen plus UVA (PUVA)
- A combination of broadband UVB/UVA light
treatment
- Broadband UVA exposure
- Broad-band UVB exposure
- Narrowband UVB (311 nm)
- UVA-1 (340-400 nm)
PUVA should be restricted to acute and complex atopic dermatitis. It
can also be used in combination with topical steroids to minimize the
use of the latter and hence its side effects. Among the other phototherapies,
broadband UVB is the least effective of the lot.
The side effects of phototherapy are stinging, burning, premature ageing
of the skin, pigmentation and the risk of squamous cell carcinoma and
melanoma. Moreover, there are chances of a relapse generally within 3
months after phototherapy is stopped.
Antimicrobials
Antimicrobials in the form antibiotic drugs are prescribed in the case
of microbial aggravation of atopic dermatitis. Microbes such as bacteria,
viruses, fungi and yeast can worsen an atopic dermatitis condition. Antibiotics
are a must for cases with a S. aureus infection, with a preference for
systemic antibiotics and first generation cephalosporins. Antimicrobial
therapy with acyclovir is vital in atopic dermatitis patients with (generally
life threatening) eczema herpeticum infection.
Eczema molluscatum infections generally heal on their own, but with treatment
the condition can be improved and proliferation deterred by autoinoculation.