Protopic effective for nickel-induced allergy

NEW YORK (Reuters Health) – Protopic, also known as
tacrolimus 0.1 percent ointment, suppresses the signs and
symptoms of skin allergy resulting in contact dermatitis among
individuals who are sensitive to nickel and who continue to be
exposed to this metal, a new study shows.

The investigators used nickel to create an experimental
model of chronic allergic contact dermatitis. “Theoretically,
since the mechanism of action is the same,” tacrolimus ointment
would be effective in allergic contact dermatitis induced by
other compounds, Dr. Donald Belsito from the University of
Missouri in Kansas City told Reuters Health.

Allergic contact dermatitis — characterized by
inflammation, rash, itching and blistering — is one of the
most common occupationally related conditions in the United
States, costing an estimated $1 billion annually due to lost
work, reduced productivity, medical care and disability
payments.

Nickel induces allergic reactions in roughly 5.8 percent of
the U.S. population, making it an appropriate model for
studying allergic contact dermatitis.

In the Journal of the American Academy of Dermatology,
Belsito and colleagues from several other U.S. institutions
report the results of tacrolimus 0.1 percent ointment treatment
in patients with nickel-induced allergic contact dermatitis.
Ninety-one patients were evaluated for the effectiveness of
tacrolimus and 97 were evaluated for the safety of the drug.

The patients, who were 17 years of age or older and had a
history of nickel allergy, applied a thin layer of tacrolimus
ointment to the upper inner side of one arm and an inactive
placebo ointment to the other arm, twice daily. The subjects
were then randomly assigned to receive a nickel containing
patch or a placebo-ointment patch for 4 to 8 hours each day.

Tacrolimus ointment was significantly more effective than
the placebo ointment in ameliorating the signs and symptoms of
nickel-induced allergic contact dermatitis. After 8 weeks,
dermatitis was clear or almost clear in 45 percent of patients
who received tacrolimus, but in only 1 percent of those who
received the placebo, they report. The statistically
significant response occurred as early as day 8.

The rate and type of adverse events were similar in the
tacrolimus and placebo groups. Side effects at the application
site included swelling, itching, rash, pain, along with
bruising and burning — each occurred in 2 percent or fewer of
the study subjects. A total of six patients discontinued
treatment due to application site events. Twelve adverse events
were the result of injury caused by removing the tape used to
secure the nickel patches.

Unlike topical steroids, topical tacrolimus does not cause
thinning and other changes to the skin and are less likely to
be absorbed throughout the body, Belsito told Reuters Health.

Preventive treatment with topical tacrolimus, he concluded,
provides “a worker allergic to a given chemical in the work
environment (for example, a hairdresser allergic to hair dyes)
an alternative to giving up their profession, dealing with
chronic hand dermatitis, or taking the risks of chronic topical
steroids or oral medications with even greater risks.”

Tacrolimus is available by prescription only to treat
moderate-to-severe allergic dermatitis in patients who can’t
take or don’t respond to other topical allergy drugs. Last year
the FDA issued a warning, based on animal studies and a small
number of patient reports, of a possible risk of cancer
associated with the drug. However, a relationship between
tacrolimus and cancer has not been proven.

The study was supported by Deerfield, Illinois-based
Astellas Pharma US, Inc, maker of Protopic.

SOURCE: Journal of the American Academy of Dermatology,
July 2006.