ISTM Study Group
#45 Tropical Skin Disorders –
Post Travel Management
Submitted by:
June Armstrong RN(EC)
ajune@region.waterloo.on.ca
tel: (519)883-2006x5277 or (519)883-2007
fax:(519)883-2248
Most frequent skin
problems in travelers:
- cutaneous larva
migrans
- insect bites,
secondary infections
- pyodermas
- non-specific
dermatitis
- chronic dermatitis
(eczema, psoriasis)
- photodermatitis
(sunburn)
Cutaneous Larva Migrans (CLM)
- most common
serpiginous (linear, like a snake) lesion
Acquisition
- travel tropics (common
Caribbean), barefoot on beach
- hookworm larvae
contaminated with dog or cat feces –penetrates intact skin
Diagnosis – clinical
- severe pruritis, linear/serpiginous
tract with or without bullous changes
- moves 2-3cm/day
- lesions most common
feet, also on hands, buttocks, genitalia (if exposed)
- differential
diagnosis – strongyloidiasis (larva
currens)– perianal only, moves much faster up to 10cm/hr with prolonged
symptoms, infects lungs and intestine, dx by serology and stool for O+P
Treatment
- self-limited but may
last weeks, and rarely up to a year if not treated
- topical
thiabendazole 15% drug of choice, alternates – albendazole or ivermectin PO
for extensive lesions – side effects with PO
Tungiasis (chigoe, jigger,sand flea) “jiggers”
Acquisition
- Africa most common, also
South and Central America
- female sand flea burrows
into foot – between toes, the nails, sole
- T penetrans
found sandy soil esp. around pigsties and cowsheds
Diagnosis - clinical
- painful nodule ~ 5-8 mm
with black dot in centre foot, often under toenail
- complications -
secondary infection, tetanus
Treatment
- surgical evacuation of
the flea that is lodged in the burrow with needle
- ensure tetanus UTD
Myiasis (Bot or Tumbu fly)
Acquistion
- Bot fly (Central + S.
America) eggs ->on mosquito/insects -> human when bitten
- Tumbu fly (Africa) eggs
-> shady soil or clothing hanging to dry or on ground
(hence the recommendation to iron clothes -> kills eggs)
Diagnosis - clinical
- mildly painful
subcutaneous swelling, looks like a boil but:
- has central opening,
maggot able to protrude/breathe
- patients may feel
movement
Treatment
- suffocate with Vaseline
(or uncooked bacon) – cover with toothpaste cap and tape for up to 24 hours,
pull off and larvae should pop out
- if doesn’t come out,
extract with venom extractor (by Sawyer), or lateral pressure
Cutaneous Leishmaniasis (sandfly)
Acquisition
- Central and S. America
most common, Dominican Rep., Asia, Africa, Mid East
- female sand fly, dusk to
dawn biters, more common rural
Diagnosis – smear,
biopsy, culture
- weeks-months after bite
- painless papule -> nodule-> ulcer, raised margins, crusted base
- chronic over many months
- smear, biopsy, culture –
NB to identify species
Treatment
- not all species require
tx, some can spread to other sites
- supportive, local heat,
topical or systemic sodium stibogluconate (Pentostam), itraconazole,
allopurinol
Phytophotodermatitis (plant + sunlight = dermatitis)
Diagnosis – clinical
- lime juice onto skin in
sun (psoralen compounds) ->UVA sensitization
- painless, non-pruritic,
hyperpigmented straight streaks or droplets
- resembles sunburn
Treatment
- spontaneously resolution
eventually
Phytodermatitis (plant -> dermatitis)
Diagnosis – clinical
- irritant or allergic
reaction to plants (i.e., poison ivy, houseplants) or fruit i.e., mango,
pineapple
- erythema, papules,
vesicles, edema, bullae
Treatment
- topical or systemic
corticosteroids
Insect Bites
- most frequent papular
lesions
Diagnosis – clinical
flea bites
- fleas, bedbugs, reduviid
bugs – clusters or linear in 3s (breakfast, lunch, dinner)
- reduviid “kissing” bugs,
adobe brick/mud huts, Americas -> Chagas’ disease (American Trypanosomiasis)
- deer, tsetse, black
flies – painful
- deer fly – rural rain
forests, West Africa ->Loa loa (itchy painful s/c swelling x1-3 weeks,
worm migration across sclera or eyelid)
- tsetse flies – rivers,
savannah Africa -> African Trypanosomiasis (sleeping sickness)
- black flies –
onchocercal dermatitis (Filiarisis) – Africa, C.+S. America – long stay
travelers, very pruritic rash trunk, lower legs and painless nodules
- chigger mites(Scrub
typhus) – grasses/shrubs worldwide, rural – pruritic, legs, belt line, last
the longest
- and of course those
pruritic mosquito bites
Papular urticaria –
persistant hypersensitivity reaction to insect bites
- papules come and go for
weeks to months after bites/return from trip
- more common young
children, unusual > age 7 yrs
Treatment (of bites or
urticaria)
- topical corticosteroids,
hydroxyzine (Atarax)
Pyodermas
ecthyma
- very common (group A
strep or s. aureus)
- may be precipitated by
hot, humid weather, poor hygiene
- may be secondary to
infected bites or skin trauma
- includes impetigo,
ecthyma (ulcerated), furuncle (boil), folliculitis
Diagnosis – clinical,
swab C+S PRN
- consider nasal swab C+S
to R/O nasal carriage if recurrent
- ecthyma – shallow,
painful ulcer post infected bite/skin trauma
Treatment
- antibiotic tx – topical
i.e., mupirocin(bactroban) or oral i.e., cloxacillin, clindamycin
- Rifampin or topical
mupirocin to nose if colonized to prevent recurrence
- I+D if needed
Miliaria Rubra (Prickly Heat)
Diagnosis – clinical
- blockage of sweat glands
- spares hair follicle
areas
- papular or vesicular,
confined to covered areas of body – pruritic or stinging
Treatment
Pityriasis(Tinea) versicolor
- one of most frequent
pigmentation disorders in returning travelers
- also common developed
countries
Diagnosis
- hyper or hypopigmented
scaling patches upper trunk, neck (often on back)
- not pruritic,
asymptomatic
- apply scotch tape to
scales, pull off and apply to drop of methylene blue onto slide ->
“meatballs and spaghetti” spores and hyphae visible with microscope OR
- scraping of scales ->
lab microscope with KOH
Treatment
·
topical terbenafine (Lamisil),
clotrimazole, ketoconazole, or selenium sulphide (selsun shampoo)
Cercarial dermatitis (swimmer’s itch)
Diagnosis – clinical for
dermatitis
Bird
schistosome larvae penetrate skin – common Great Lakes Canada/North USA
- pruritic, urticarial
rash minutes -24hrs after, on water exposed uncovered areas
- rash more common and
severe than human form
- transient, may last up
to two weeks
- no risk chronic illness,
do not mature in humans
Human
shistosome larva penetrate skin – Africa, S. America, Asia
- component of acute phase
of schistosomiasis
- uncommon to see a rash
esp. with primary exposure – likely a sensitization
- see outline #36 for
details re human schistosomiasis infection
Treatment (of
dermatitis)
- antihistamines, topical
or systemic corticosteroids
Seabather’s eruption
Acquisition
- larval sea anemone (Long
Island, NY)
- thimble jellyfish
(Florida, Caribbean)
- nematocysts sting the
skin under swimwear-> allergic rn
- swimmer may recall
stinging or prickling sensation in water
Diagnosis - biopsy
- papular, pruritic,
burning rash
- onset <24 hrs lasts up
to 4 weeks (usually 1-2 weeks)
- only under bathing
suit
- fever, headache, nausea
esp children
Treatment
- antihistamines, topical
and systemic corticosteroids, isopropyl alcohol, vinegar
Sea
Urchin Spines
Diagnosis – clinical
- immediate - pain, edema,
embedded spine(s)
- delayed - edema,
cyanosis
- late – foreign body
granuloma, nodules
Treatment
- pain relief: hot water
45 degrees C, 30-90 mins
- 5% acetic acid (vinegar)
to inactivate toxin
- shave or scrape off
spines
- if delayed rn – systemic
steroids
- if late rn:
intralesional steroid, excision
Cnidaria dermatitis (jellyfish, Portuguese man-of-war)
Diagnosis
- nematocysts in skin,
fresh water and rubbing triggers release of toxin
- immediate stinging,
burning, numbness or paresthesia
- linear, urticarial,
vesicular or ulcerative, hyperpigmentation when healed (wks-months)
Treatment
- rinse in sea water,
avoid fresh water, don’t rub
- 5% acetic acid (vinegar)
to inactivate toxin
- shave or scrape off
tentacles
- severe cases –
tourniquet, steroids, epinephrine
- box jellyfish -
antivenom
Tick
Eschar
Acquisition
- tick typhus -
Mediterranean, Africa, India
Diagnosis
- black eschar with
erythematous margin (similar to Anthrax but less swelling)
- located at clothing
constrictions
- may have low platelets,
low WBC
Treatment
- pull out slowly with
forceps or tweezers (don’t cut it out)
Leprosy
Diagnosis
- nonhealing, numb,
hypopigmented patches (copper colour in dark skin)
- clinical - thickened
peripheral nerves, diagnostic - slit skin smears, biopsy
Treatment
- multi-drug therapy-
dapsone, rifampin, clofazimine
Although common in the
tropics the following skin lesions are not included; they are also seen in
developed countries:
- scabies
- cutaneous candidiasis
- drug reactions
- herpes simplex
- atopic dermatitis/eczema
- psoriasis
- urticaria
- pseudomonas
folliculititis (hot tub folliculititis)
- fever and rash i.e.,
measles, meningococcemia, scarlet fever, parvovirus etc.
- photodermatitis
(sunburn)
References
1.
Tan S., Keystone
JS: Skin Lesions in the Returned Traveler. The Canadian Journal of Diagnosis
2000:85-95.
2.
Kain KC: Travel
Medicine CME: Skin Lesions in Travellers, Tropical Dermatology, University of
Toronto, May 13, 2000.
3.
Keystone JS:
Tropical Dermatology. Travel Medicine Advisor.
4.
Mandell GL,
Bennett JD, Dolin R: Principles and Practice of Infectious Diseases, 5th
ed. 2000.
5.
Chin J: Control
of Communicable Diseases Manual, 17th ed. 2000.
6.
Fitzpatrick TB,
Johnson RA Wolff K, Suurmond D: Color Atlas & Synopsis of Clinical Dermatology,
4th ed.McGraw-Hill, 2001.
flea bites
ecthyma
