Download Ivermectin use in Scabies

PRESENTER
DR. MD. ABDAL MIAH
ASSISTANT PROFESSOR
DERMATOLOGY & VENEREOLOGY
MYMENSINGH MEDICAL COLLEGE,
MYMENSINGH
CHAIRED BY
DR. MD. SHAHAB UDDIN AHMED CHOWDHURY
Associate Professor & Head
Department of Dermatology & Venereology
Mymensingh Medical College, Mymensingh.
TODY’S TOPIC
IS
IVERMECTIN
USE IN SCABIES
Source: American
Family
(Review Journal)
Physician
Sept 15, 2003, V-68, P-1089-92
INTRODUCTION
Scabies is a skin disease caused by
infestation with the mite female gravid
sarcoptes scabiei var hominis. Scabies has
been a problem for humans since before the
first millennium and was reported by the
earliest writers who described mankinad’s
health problems. It is estimated that there
may be 300106 cases of scabies worldwide
each year. Mostly, scabies is treated with
topical scabicides, which needs to be used
over whole or nearly whole skin surface,
which is a difficult process.
So, non compliance or improper use of
topical scabicides can result in scabies
as a public health problem. So, the time
honored
demand
was
for
systemic
alternative. Now, oral ivermectin has
appeared
as
an
effective
and
cost-
comparable alternative to topical agents
in the treatment of scabies infection.
DIAGNOSIS OF SCABIES
The
diagnosis
clinical
but
microscopic
mite,
eggs
of
may
scabies
be
confirmed
identification
and
usually
scybala
of
is
by
female
in
skin
scrapings.
Key points for the diagnosis of scabies
are the following:
1. Morphology of skin lesions (i.e. type of
eruptions)–
Pathognomonic lesion– Linear burrows.
Nonspecific- Papular or papulovesicular or
vesiculo-pustular lesions.
Excoriations and ulcerations.
Urticarial lesions- rarely.
2. Typical distribution–
Common sites (irrespective of age
and sex).
Finger-webs, flexor surfaces of
wrists, flexor surfaces of elbows,
axillae, umbilicus,
waistband,
gluteal crease.
Male-
genitalia
Female- breasts (Areola and Nipple)
Infants and young childrenScalp, face, palms and soles
3. Pruritus– Usually intense, disproportionate
to the amount of eruptions, worse at night
and pleasant in quality.
4. Positive history in skin contacts.
5. Definitive diagnosis rests on identification
of the mites or its products.
Useful diagnostic methods:
a) Direct examination of skin scrapings
under low power objective.
b) Dermoscopy.
c) PCR.
TREATMENT
A. Treatment of patients: It includes
i)
Treatment of complications
ii) Symptomatic treatment and
iii) Specific treatment with scabicides.
Topical and systemic scabicides:
a. Topical scabicides include
– Precipitated sulfur 6% or 7% in
petroleum jelly
– Benzyl benzoate emulsion 25%
– Monosulfiram- a 25% solution
– 1% Gamma benzene hexachloride
(lindane)
– Malathion 0.5%
– Crotamiton 10%
b.
Systemic scabicide- oral ivermectin 200
gm/kg- Single dose, may have to be
repeated.
B. Treatment of contacts.
C. Trcatment of house-hold utensils.
IVERMECTIN
 First it was developed in the 1970s as a
veterinary treatment for animal parasites.
 It is a member of a family of macrolytic
lactones, the avermectins.
 It has broad spectrum activity against
parasites such as
FDA approvedStrongyloidiasis
Onchocerciasis.
Not FDA approved- Filariasis
Cutaneous larva migrans.
Scabies.
Pediculosis etc.
An estimated 6 million people world-wide
have taken ivermectin for various parasitic
infestations.
 Since 1993, it has been successfully
used in different countries to treat
human scabies that is resistant to
treatment.
 Some of the study results are shown
below:
Study
1
2
3
4
No. of patients Cured (%)
26
96.15
11
100
100
83
11 (with AIDS)
70*
>90**
Not Cured (%)
3.85
00
17
30*
<10**
Many other studies done by different
groups such as Glaziou P et al, Dunne
CL et al, Kar SK et al, Shouela EN et al,
Madan V et al, Usha V et al also
confirmed the efficiency of ivermectin
as a treatment of scabies infection.
SAFETY OF IVERMECTIN:
Adverse effects such as anorexia, nausea,
vomiting,
rash,
headache,
dizziness,
arthralgia, itching, eosinophilia, abdominal
pain, fever, tachycardia etc may occur but
occur very infrequently. No serious drugrelated adverse events or significant drug
interactions have been reported.
But
its
safety
in
young
children
pregnant women– not established.
and
A comparison of ivermectin with 5%
permethrin is shown below:
Drug
Efficacy
Ivermectin
83-100%
Permethrin
91-98%
Adverse
effects
Cost
anorexia,
Tk. 40*
nausea,
Tk. 80**
vomiting, rash,
headache,
dizziness,
arthralgia,
itching,
eosinophilia,
abdominal
pain, fever,
tachycardia etc
Pruritus,
burning,
stinging
Tk. 40*
Tk. 80**
Use in
children
In
pregnancy
Nursing
women
Safety not
proved in
children
<15 kg or
<5 years
C
Not
recommended
Safe in
children
2 months
B
Not
recommended
Superiority of ivermectin over others:
1. Easy route of administration– oral.
2. Dose convenience– only single dose.
3. Efficacy– very high- 98-100%.
4. Safe– very infrequent side effects and not a
single major adverse event over 6 million
users.
5. Cost effective.
So, many authors and publications
consider it to be the treatment of choice.
CONCLUSION
Oral ivermectin, because of its single oral
dosing, very high efficacy and safety, and low
cost, may replace the other topical agents in
the treatment of scabies. It may be particularly
useful in the treatment of severely crusted
scabies
lesions
in
immunocompromised
patients or when topical therapy has failed or
application
of
topical
agents
is
logistically
difficult (e.g. large institutional outbreaks or
mentally impaired patients).
MESSAGE
 We know the cause
 We know the mode of transmission
 We have multiple weapons to fight against
this mite.
 But
this mite is winning the battle
affecting 300 million peoples each year
around the globe.
So, IVERMECTIN may be the best weapon
to win this battle.