A randomized controlled trial to asses the effect of topical vitamin D in patients with atopic dermatitis.

Atopic dermatitis (AD) is a common relapsing chronic skin disease. One of the
contributing etiologic mechanisms is an impaired epidermal barrier. The
epidermis in AD has a higher proliferation rate, and less differentiation than
skin of healthy controls. A loss-of-function mutation in FLG is associated with
AD. This gene encodes for filaggrin, an important component of the epidermal
barrier.
AD is treated with topical corticosteroids that have several side-effects.
Finding new treatment options is therefore needed. Vitamin D has proven to have
beneficial effects on AD. Topical vitamin D3 analogues show an improvement of
the epidermal barrier, with little to no side-effects, but have never been
examined for the effects on AD. Therefore, we will examine the effects of
topical vitamin D on AD. The expectation is that administering these ointments
to patients with AD will reduce the symptoms.

The main study objective is to determine the time to, as well as number of
exacerbations of atopic dermatitis in the study period between the study groups
A and B.
The secondary objectives are the differences in transepidermal water loss and
Quality of Life between the study groups.

Single blind, randomised control, intervention study

Patients in the first group will be treated with the golden standard for atopic
eczema: corticosteroid ointment; specifically mometason ointment. The second
group of patients will be treated with vitamin D ointment as active treatment.
Both groups are allowed to use several kinds of emolliens as maintenance
treatment.

Burden and risk associated with participation are low. Subjects will be asked
to visit the out-patient clinic 3 times, in 4 months. The overall data is
acquired by physical examination, non-invasive measurement (quality of live
questionnaires and TEWL-measurement) and 2 venapunctures (for assessment of
their vitamin D level).
Patients will be asked for permission to check their DNA for a filaggrin
mutation; this can be obtained with a cheek swab. Patients are free to refuse
this test.
The investigational drug, calcitriol ointment, has already been registered for
use in another skin disease and has been shown to have little to no side
effects.