Transcript D folliculorum

Clinical Importance of
Demodex folliculorum in
patients receiving
phototherapy.
Kulac et al, International Journal
of Dermatology 2008, 47, 72-77
Introduction
Demodex follliculorum is a 0.3mm long,
obligate, hair follicle parasite which lives in
cluster in the pilosebaceaous duct and has a
pathogenic thought role in pityriasis
folliculorum, perioral dermatitis, blepharitis,
rosacea, eruptions resembling rosacea, and
pustular and granulomatous folliculitis.
The density of mites in healthy skin is age
dependant and reaches 100% in elderly
people.
One of factors responsible for
colonization of mites is development of
primary or secondary
immunosuppression (AIDS…).
Phototherapy is widely used and is
thought to act primarily through its
immunosuppressive effects. It also
increases the amount of skin surface
lipids by direct activation of the function
of sebaceaous glands.
Materials and methods
Selection of patients:
psoriasis and vitiligo from JAN to Feb 2005
exclusion criteria: previous or actual rosacea,
perioral dermatitis, or dermatosis related to D.
Folliculorum, immunosuppression, diabetes, the use
of antibiotics and sunbathing in the last three
months.
-24 female and 21 male (45) 36.61 years and
43 sex and matches healthy controls(outpatient
dermatology clinic)
-sociodemographic, professions, skin types
recorded
-PUVA or NBUVB dosage and number of
treatments recorded.
Phototherapy protocol applied
-Waldmann cabinet
-dosage 0,5J/cm2 x phototype 3 times a
week with increments of 0,5J/cm2
-for PUVA: oral 8-methoxypsoralen
0,6mg/Kg 90 min before exposure
-for NBUVB 0,7MED initial dose and
increments of 20%.
Sampling method:
-standardised “surface” skin biopsy on
forehead, cheek and nasal dorsum= non
invasive sampling method which involves
placing a drop of cyanoacrylic adhesive on a
microscope slide, applying the adhesivebearing surface of the slide to the skin, and
removing it gently after it had been allowed
to dry.
- scotch test removal, clarification with
immersion oil and microscope study
performed by the same investigator.
-Evidence of D folliculorum was defined if
5 or more mites were present per square
centimeter.
Clinical findings and clinical demodicinosis
types:
-In the patient group, the clinical findings
(erythema, telangiectasia, follicular tiny papule,
follicular tiny pustule, follicular scaling, papule,
pustule, nodule and abscess) were recorded.
-clinical diagnosis of demodicinosis was done
if microscopic evidence was present.
Statistical analysis
-mean and SD.
-differences were assessed using X2 and
Fisher exact tests in nominal variables.
-Intergroup D.folliculorum densities were
made using the Mann-Whitney U-test and
significance was assumed if p smaller then
0.05.
Results
Demodicinosis was detected more frequently in
patients receiving phototherapy than in the control
group: 13 patients in the phototherapy group and 3
in the control group.
In 8 of the 13 patients, clinical demodicinosis was
present. The 5 other didn’t have clinical signs.
In 6 patients ( 2 NBUVB), the clinical picture was
pityriasis folliculorum.
In the 2 other patients (1 PUVA), the clinical picture
was rosacea.
1 patient (NBUVB) perioral dermatitis was present
but no demodicinosis was present.
1 patient for PUVA for psoriasis developed sunburn
and developed erythema and pustules on the face
and demodicinosis was present.
In those 15 patients, no difference in the
number of treatments with PUVA (39.58 +/30.81, cumulative dose 78.07 +/- 69.82
J/cm2) and NBUVB (48.54 +/- 32.01, CD
171.22 +/- 193.59 J/cm2)
-No difference in the skin types
-Demodicinosis in 7 of 12 patients with
PUVA and 6 of 33 patients in NBUVB
-The highest density was found on the
cheeks
Discussion
This is the first study relating demodicinosis and
phototherapy. Only on case report was available in
the literature.
The increase in D folliculorum may have been
caused by immunosuppression and enlargement of
the sebaceaous glands as a result of phototherapy.
It is also well known that rosacea is exacerbated
by sun and heat.
Although the pathogenic relationship between
D.folliculorum, rosacea and sunlight is not
completely understood, it is possible that increased
blood flow in dilated papillary dermal vessels by
the effect of solar radiation may provide a
favorable environment.
Rosacea is always associated with solar
elastosis, and solar degeneration of
connective tissue is important in its
origin. There is also a seasonal
tendency for rosacea to be exacerbated
in the spring (sebum production also
increases in the summer and after 4
days of UV irradiation)
Immunosuppression, old age, topical and
systemic steroids, calcineurin inhibitor usage
and diabetes are predisposing factors for
demodicinosis. D folliculorum increases in
incidence in patients with AIDS, diabetes and
hematologic malignancies. (T cell deficiency,
decreased CD3+, CD4+, CD8+, CD16+,
CD3+/CD20 ratio, 2,5 times increased CD95+
(apoptosis marker) for selection of T and B
lymphocyte selection).
the incidence of demodicinosis in patients on
phototherapy is similar than in patients with
hematologic malignancies.
Conclusion
Immunosuppression and sebaceous
gland enlargement from phototherapy
can contribute to the development of
demodicinosis. The authors believe that
demodicinosis should be included in the
differential diagnosis of facial eruptions
in patients receiving photoherapy. It is
therefore recommended to perform a
routine surface skin biopsy in that case