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SKIN DISEASES IN THE TROPICS, :black_medium_small_square: Can be…
SKIN DISEASES IN THE TROPICS
:eight_pointed_black_star:
Leprosy
:point_right:
Caused by the bacterium Mycobacterium leprae
targets the skin and nerves
:black_circle: The
skin is affected early in the course of the infection
:black_circle: It is transmitted directly through
close contact over long periods
:check: Transmitted via
droplets,
from the
nose and mouth
During close and frequent contacts with untreated cases
If untreated
:red_circle: These
neuropathic ulcers
, can proceed to
destroy other structures in the area
(bone)
First signs
:large_orange_diamond: They are usually
skin patches of variable sizes
:black_medium_small_square:
Usually dry
and whose
colour may be slightly paler
than the rest of the skin
:large_orange_diamond: OR It takes
the form of multiple lumps
:red_circle: Patients
cannot feel hot objects or rubbing shoes
Ulcers form at these sites
:eight_pointed_black_star:
Cutaneous leishmaniasis
:point_right:
Infection of the skin or oral mucosa caused by Leishmania protozoa
:red_flag: Spread through
biting insects, sandflies
of the genera
Phlebotomus, Lutzomyia and Psychodopygus
Wild animals, domestic animals and humans
:white_medium_square:
Lumps on the skin
that can
be rounded or flat
and which
may ulcerate in the centre
:arrow_right:
Ulcer edges or borders are often raised
:arrow_right:
Lesions may be single or multiple
usually
occurring on exposed sites such as the face or limbs
:keycap_star:
The base of the ulcer is usually red and bleeds easily
May affect any age group
Normally occurs sporadically
:keycap_star: Lesions may also occur
in the mouth or nasal passages
:black_circle_for_record:
Visible changes may vary in different parts of the endemic range
In areas of South America
:eight_pointed_black_star:
Buruli ulcer
:point_right: Caused by
Mycobacterium ulcerans
:red_flag: Mode of transmission is not known
:black_medium_small_square:
First changes
:white_medium_small_square:
Raised lumps on the skin that subsequently ulcerate
:arrow_right_hook: They are usually
single and large
:arrow_right_hook: With a
yellowish surface appearance
and an
underlying red moist base
:arrow_right_hook:
Edges are often undermined
sometimes 2–3 ulcers
:black_medium_square: During the
early stages of infection
:point_right::skin-tone-6:
Extensive swelling
may extend around the emerging ulcerated area
:arrow_lower_right:
Children aged under 15 years.
In many cases there is associated exposure to rivers, streams or wetlands
:eight_pointed_black_star:
Post kala-azar dermal leishmaniasis
:point_right:
It is a complication of systemic or visceral infection with Leishmania
:small_red_triangle:
5–20% of patients
who have visceral leishmaniasis
develop skin lesions as a late complication
:small_red_triangle: These
lesions are usually either pale patches, or small or large lumps
:large_blue_circle: May
occur at any age
but develops in around 10–30% of patients some 6–12 months
after apparent resolution of visceral (internal) leishmaniasis
:eight_pointed_black_star:
Lymphatic filariasis
:point_right:
Systemic infection
caused by the
filarial nematode worms
Wuchereria bancrofti
:black_circle: They
live in, dilate and obstruct the lymphatic channels
:black_small_square: Usually in the
lower parts of the body
(
the groin - genital area and thighs
)
:black_square_button: It is transmitted by
mosquitoes such as Culex and Anopheles
:black_square_button: Impair
lymph flow
:arrow_right: leading to
progressive swelling or lymphoedema of the lower limbs
:arrow_lower_right:
In males, swelling of the scrotum (hydrocele)
:arrow_lower_right:
Breasts or vulva in females.
:black_square_button: Often
starts in childhood
, it becomes
prominent in adults
:eight_pointed_black_star:
Hygiene and skin care
are
important to prevent secondary bacterial infections
Skin, lymph vessels and lymph glands
:red_circle:
Adenolymphangitis or acute dermatolymphangioadenitis
progress the severity of disease
Affected area is warm, reddish and painful
:black_square_button: The skin
may become thickened
, covered in
small lumps
giving a
cobbled appearance
:eight_pointed_black_star:
Mycetoma
:arrow_lower_right: Infection under the skin :point_right::skin-tone-5: development of a
large lump
(usually painless)
As this enlarges
it becomes covered in smaller lumps
:black_small_square:
Some are filled with pus
:point_right::skin-tone-6:
Infection of the subcutaneous tissue and bone
caused by a variety of
different environmental bacteria and fungi
:arrow_right: through a
deep skin injury such as a thorn prick
:black_medium_small_square:
In advanced mycetoma
The bone in the area is invaded with local destruction
:arrow_lower_right: The part of the limb or body affected becomes
swollen and deformed
:black_circle:
Adults are mainly affected
:eight_pointed_black_star:
Onchocerciasis
:black_joker:
Affects the skin and the eye
:black_joker: The adult female worms form
firm subcutaneous or deeper large lumps or nodules
:arrow_right_hook: People are most likely to
complain of troublesome itch
Symptomatic skin signs
:black_circle:
Iritis
(inflammation near the pupil of the eye)
:point_right: produced by the
inflammatory response to dying microfilaria
(an early larval form of the parasite)
:black_circle:
Corneal scarring
:black_circle:
Retinal damage
(retinopathy)
:point_right:
Caused by Onchocerca volvulus
:arrow_lower_right: Transmitted by
black flies of the genus Simulium
that breed
near fast running streams and rivers
:arrow_lower_right: As the
disease progresses
the
skin becomes wrinkly
and
skin folds can enlarge and sag
:arrow_right: In the
groin (hanging groin)
:arrow_right:
Visible depigmentation may occur (leopard skin)
:black_joker: Accompanied by
small itchy lumps on the skin
(around the shoulders or waist and thighs)
:red_circle: Sometimes
appear more densely on one limb than the other
:red_flag: The skin of the affected limb becomes
rough, chronically itchy and with thickened patches
That are darker in colour than the rest of the skin
:black_circle: Most cases are recognized in
older children or adults
:eight_pointed_black_star:
Scabies and other parasitic infections
:white_circle: Transmitted by
human to human contact
:arrow_lower_right: Iit can
affect all age groups
(particularly common in infants and children)
:point_right:
Caused by the human itch mite Sarcoptes scabiei
:arrow_lower_right: In
resource-poor settings
and is associated with
household overcrowding
:white_circle: The
skin in certain areas
is covered with
small lumps, some containing pus
as well as
small squiggly lines
:black_circle:
Hands, feet, external genitalia, buttocks and shoulders
are all commonly affected
Secondary bacterial (streptococcal) infection
:white_circle: May cause
kidney inflammation or nephritis
, an
immunological reaction to the bacteria
(in children)
:red_circle:
Tungiasis
:point_right::skin-tone-6: An itchy infection
caused by a tropical sand flea Tunga penetrans
:white_circle: Causes
itchy lumps
, usually
with a central dark or pus-filled plug
commonly on the feet after contact with contaminated sandy soil
:eight_pointed_black_star:
Yaws (endemic treponematosis)
:point_right: A
systemic infection
affecting the
skin
and,
more rarely, bone
:point_right:
Caused by the bacterium Treponema pertenue, a subspecies of T. pallidum
:chestnut: It is often first
recognized in children but may affect all ages
:chestnut: Spread by
direct contact between individuals
:black_medium_square: Presents with
one or multiple skin lesions
, which appear as
small lumps or nodules.
:arrow_right_hook: May break down to
leave an area of ulceration
in the centre of the nodule or appear in the shape of a small volcano
:arrow_lower_right: May have a r
ed or yellow surface colour and often feel soft, pebbled or bumpy
:eight_pointed_black_star:
Other common
:point_right: Caused by
Staphylococci
:black_square_for_stop:
(such as impetigo or boils)
:point_right:
Streptococci
:black_square_for_stop:
Impetigo
:point_right::skin-tone-6:
Superficial fungal skin infection or tinea
:black_circle_for_record:
Caused by fungi
:black_circle_for_record: Infect the outer layers of the skin to cause
scaly, itchy patches on the body, legs or scalp
:black_circle_for_record: In the
head
there is also
loss of hair
:point_right::skin-tone-6:
Eczema (dermatitis)
:black_square_for_stop: Causing
scattered itchy dry patches with scaling on the skin of the arms
,
legs, face
and
body
:red_circle: It is a
common non-infectious skin problem
:large_orange_diamond: It is
common in children
:point_right::skin-tone-6:
Insect bites
:arrow_lower_right: Which are
scattered itchy lumps on exposed sites
:black_medium_small_square: Can be
transmitted from human to human in homes or schools
