DISEASES DUE TO
Lice are vector of
certain diseases that may cause cutaneous and systemic diseases such as
relapsing fever and typhus .
Two species of
lice can infest human body :
humanus (head louse). This can infest the scalp and body causing
pediculosis capitis and pediculosis corporis .
pubis: infests the pubic hair and the anogenital areas.
Fig. 133. Pediculosis capitis
(Nits along the hair shaft)
capitis is a common infestation of girls and boys with long hair. A school
child is commonly infested due to direct contact with others in the
classroom or in the playing ground. Infestation from personal fomites such
as combs , hairbrushes and hair covers is common .
The commonest area
infested is the occipital area and that which is near the ears. Lice are
sometimes not easily found in the infested area but the nits are seen on
the hair shaft .
bacterial infection causing folliculitis, impetigo and furunculosis.
Fig. 135. Pediculosis capitis
Fig. 134. Pediculosis capitis
(Secondary bacterial infections)
The hair may be
matted together with offensive smell due to the oozing and crusted
occipital lymph nodes are enlarged .
Constitutional symptoms especially in infants and children are due to
toxic bacterial absorption.
the nits on the hair shaft or the parasitic lice .
should be suspected in any case of :
scalp lesions .
the occipital or posterior cervical lymph nodes especially in young girls.
bacterial infection is treated first.
lesions are treated by wet compresses such as Potassium permanganate
1:9000 twice daily followed by topical antibacterial preparation such as
Muperacin (Bactropan Cream).
antihistamines orally may be required to alleviate itching .
hexa chloride ( Kwell lotion or shampoo ) is applied and rubbed to the
scalp at night and shampooed next night .
application may be required after two weeks .
This is an
infestation of the body caused by body louse. The parasite is rarely
detected on the skin . It is found clinging to the clothes where it
pierces its probiscus into the skin and sucks blood .
itching, which may be severe. Excoriation of the skin with manifestations
of secondary bacterial infections. Impetigo and furunculosis are common
complications of pediculosis corporis .
Fig. 136. Crab louse & Head louse
Fig. 137. Pediculosis corporis
The clinical picture may be
diagnostic. Erythematous macular lesions where parallel excoriation and
scratch marks appear on the shoulders . Hyper pigmentation of the affected
areas may follow which is due to the effect of saliva of the lice,
changing the bilirubin into beleverdin .
corporis is differentiated from scabies by the absence of burrows and the
hands and feet are not involved.
Detection of the
parasites or their eggs can be found on thorough search of the clothes .
infested individuals by one per cent Melathione.
) cream or lotion.
Severe itching may
need topical antipruritic preparation and oral antihistamines.
is infestation of the pubic area. This is usually the only site infested
and rarely other areas are involved as eyelashes, eyebrows, axilla and
Pubic louse is
different from other types of lice by having greater width than length .
They are small and sometimes not easily detected while their nits are
glued to the hair shaft and the louse may be seen grasping the base of the
hair shaft with their heads buried in the hair follicle.
is rare in newborn and children. Infestation occurs from infested mother
or father. Pediculosis pubis is sexually transmitted disease due to direct
contact from infested individuals. Infestation from infested clothes, bed
sheets, toilet seats and other infested garments may occur.
The pubic lice in
children may infest and reside the eyelashes producing blepheritis and
crusted lesions .
Lice may induce
sever pruritus on biting while the skin manifestations may be
inconspicuous apart from the scratch marks . A secondary bacterial
infection is common complication as furuncles , pustular lesions and even
One of the
clinical and usually diagnostic features of pubic lice is the presence of
pinpoint hemorrhagic minute spots on the underwear . Small-pigmented
steel-gray spots resembling stain may be also found on chest , thighs
,upper arms and abdomen more prominent in light skinned individuals.
Fig. 138. Pediculosis pubis (Insects & Nits)
antihistamines to relieve severe itching and antibiotics for secondary
D.D.T or Lindane spray for dusting the infested clothes.
Shaving of the
crural area may facilitate the creams or lotions to work in a better way .
Eurax lotion and cream ) once daily for two weeks is effective medication
Melathione and Gamma benzene is an alternative medications.
of bed bugs
Bed bugs are
distributed worldwide especially in crowded places , in camps and areas
with lower hygienic conditions .
The parasite has a
special smell where it attacks their victims at night to get its meal from
human blood . The parasite punctures human skin by its probiscus where it
injects a vasodilator and irritating substance into the human skin .
The reaction to
the bite varies according to the site involved , type of patients and the
age. The manifestations are more severe in infants and young children .
Mild reaction :
may show minimal manifestations . One parasite may produce several bites
mainly on the abdomen , buttocks and ankles . The reaction may be
urticarial or purpuric associated with itching at the site of the bite .
may be in the form of generalized urticarial lesions where the patient
finds in the morning that his nightdress and bed linen stained with blood
Improvement of the
general hygiene especially in crowded places .
per cent, Pyrithium or Trichlorfon spray are used to dust small holes in
the furniture, walls and floors where the parasites hide during the day.
fumigation for infested houses may be enough to eradicate the parasites .
the use of sulfur is also effective .
steroid to relieve pruritus .
antihistamines may be needed for severe cases especially for sensitive
MANIFISTATIONS DUE TO TICK BITES
Several species of
ticks attack human causing skin and systemic manifestations . Ticks are
found on grass or bushes and attack also animals as dogs .
Rocky Mountain fever , tick born encephalitis and Q-fever.
In children ticks
may cause tick paralysis if the tick is attached to the skin and not
removed immediately .
The female tick
attaches itself to the skin and sucks blood from the superficial vessels
by its probiscus till the body of the parasite becomes engorged with blood
. This may take two weeks after that the tick leaves the skin and fall .
Fig. 139-. Tick
Fig. 140. Insect bite (Papular &
- the manifestations begin by fever, chills, headache, abdominal pain and
- this occurs one week after the tick attaches itself to the neck and back
of the head of the victim . This type of paralysis, which is of the
flaccid type involves, the neck and limbs resembling infantile paralysis.
respiratory failure, dysarthria and dysphagia may be another manifestation
of the disease .
erythematous lesions with
arciform or circinate edges appear on the site of insect bite mainly on
the trunk and extremities .
hemorrhagic macules or
nodules may appear at the site where the insects bite the skin .
Erythema migrans -
The lesion has a chronic course lasting for few months.
ticks is a very important preventive measure.
DDT - dusting
crowded areas with DDT, in refugee or military camps and schools.
Removal of the
clinching tick to the skin surface leads to dramatic relief of the tick
Removal of the
tick from skin will cause relief of these symptoms within 24 hours.
Removal of the
tick should be complete. Every possible care should be considered in order
not to leave their probiscus into the skin .
Method of removal
the tick from the skin
Hold the tick
gently from the area near its mouth by a forceps, raise its body by a
needle inserted between the tick and the skin, and try to gently remove
it. The site of the bite must be immediately disinfected.
( Deet ) is very a effective repellent .
dimethyl phthalate are also effective in eradicating ticks.
diseases are systemic bacterial infections transmitted by blood sucking
arthropods such as ticks and lice.
Mountain, spotted fever, Rickettsia Pox and Scrub typhus.
Epidemic typhus is
caused by Rickettsia prowazeki, which is transmitted by lice, while rat
flea transmits Murine typhus or endemic typhus.
The organisms are
present in the feces of the lice, which by scratching or minor trauma can
penetrate the skin causing local and systemic manifestations.
symptoms - appear after an incubation period of about one week . These
manifestations include fever , chills ,aches and generalized pain.
manifestations - pinkish macular eruption appears after five days on
the trunk, which becomes later on hemorrhagic and gangrenous lesions
affecting mainly the fingers, toes, nose and the ear lobes. The face palms
and soles are usually spared .
conjunctival injection with photophobia.
disturbances such as delirium and hallucination is a characteristic of the
leads to pulse irregularities and hypotension that may lead to coma .
becomes week and debilitated .
demonstrates the antibodies in infected persons .
Fleas transmit the
disease . The clinical manifestations are the same as that of epidemic
typhus, but milder without gangrenous lesions .
(mediterranean fever )
Tick typhus is
caused by R. conori, which is transmitted by the dog tick. The disease is
endemic in countries of the Mediterranean areas and in many parts of
Africa and India. The disease affects mainly children .
at the site of the tick bite appears which later ulcerates. Characteristic
black eschar appears at the site of the bite with the febrile exanthema.
Macular or maculopapular eruption later appears on the trunk, palms and
manifestation and treatment of the disease is the same as that of epidemic
(rocky mountain spotted fever)
spotted fever is an endemic febrile disease caused by R. Rickettsia that
is transmitted by ticks from various types of animals such as rabbits,
rodents and ticks living in shrubs and grasses .
Spotted fever is
the most virulent type of the rickettsia infections. If the tick is
infected, it remains so through out its life where the virulence of the
organisms increases after the tick takes a blood meal .
period is about one week. The onset of the disease begins with a prodroma
of high fever lasting for 2-3 weeks, chills, generalized pain and
appears on the first week, begins on the wrists , ankles and then becomes
generalized with purpuric eruptions .
manifestation are due to involvement of other systems :
manifestation : meningeal irritation leads to convulsions and
Flushing of the
face and epistaxis is a common manifestation .
tick bites .
inhabited by the lice using the special repellents .
delousing is necessary to control spread of infection.
by using broad-spectrum antibiotics is curative .
the drugs of choice and treatment should be started as soon as the
clinical diagnosis is made. The drug is given in full dose as a standard
epidemic typhus and scrub typhus respond to a single dose of 200 mg
also effective and has been recommended for Rocky Mountain spotted fever
in pregnant women and children under 8 years old.
measures are necessary in
AND LYME DISEASE
This disease is
due to tick bites .
appears at the site of inoculation. The eruption appears within a week
after the bite due to spirochete inoculation. The skin lesion is usually
an erythematous ring, enlarging at a rate of several centimeters per week.
The course of the skin lesion is chronic and may take few months or even a
In some cases the
erythema is intense, in others it is rarely detectable. The erythematous
lesions may be entirely flat or show elevation at the center, or the
periphery or in both areas. Slight scaling is occasionally seen.
Older areas of
residual erythema may become dusky blue. There may be a zone of clearing
behind the advancing ring producing a target-like morphology.
or itching occurs in one third of cases.
the infection may occur within days or weeks of inoculation. Spirochetes
have been detected in the affected organs.
system manifestations :
cranial nerve palsies and peripheral radiculoneuritis.
pericarditis, conduction defects and carditis may be seen in some cases .
pains, myositis, conjunctivitis .
an infectious disease transmitted by species of Phlebotomus and is caused
by the small, rod-shaped organism Bartonella bacilliformis. The incubation
period is from 2 to 6 weeks. Two forms of infection are recognized:
These are known to
represent two stages of infection. In the first stage (Oroya fever) there
is high mortality and the second stage isVerruga peruana.
The onset is
characterized by severe pernicious anemia, leukopenia and the appearance
of immature leukocytes with a clinical picture of anemia and leukemia. The
disease may be fatal. It has a sudden onset of pyrexia accompanied by a
rapidly progressive hemolytic anemia, hepatosplenomegaly, generalized
lymphadenopathy, septicaemia and salmonella infection may appear in the
course of the disease.
cherry red, multiple hard, verrucous papules appear in crops and often
become nodular or pedunculated mainly on the face, neck and limbs.
become very large, others may be hemangiomatous or hemorrhagic petechiae
or ecchymotic rash may develop. The mucous membranes may be involved .
may develop without previous Oroya fever or may follow after weeks or
months l. Lesions may persist for months or years and lesions heal
of the disease is that the eruption may be present in different stages of
evolution in the same patient. Lesions may persist for months or years.
The diagnosis can
be reached by the following:
- The clinical picture .
- Anemia fever,
asthma, joint pains adenopathy when appear in patient has visited the
endemic area should give a suspicion .
picture: anemia, leukemia and leucopenia
detection of the spirochetes
on Noguchi leptospira medium is positive in both stages of the disease.
must be distinguished from yaws, acquired hemangiomata and Kaposi‘s
sarcoma (including AIDS).
show lesions containing numerous small blood vessels with endothelial
proliferation. There is a variable infiltrate of chronic inflammatory
In Oroya fever the
organism can be seen in blood films or isolated in blood cultures.
small doses destroys the B. bacilliformis .
g/day for a week is the treatment of choice because of the frequent
coexisting salmonella infection with the disease.
Infestation with Anoplura - lice. In: Arthropods and Human Skin. Berlin:
Springer-Verlag, 1984: 29-55.
Maunder JW. The
appreciation of lice. Proc Roy Inst Great Britain 1983; 55:1-31.
Comez MP, Austin RD et al. Comparative study of permethrin 1% creme rinse
and lindane shampoo for the treatment of head lice. Pediatr Infect Dis J
1987; 6: 252-5.
Di Napoli JB,
Austin RD, Englender SJ et a1. Eradication of head lice with a single
treatment. Am J Public Health 1988; 78: 978-80.
Epidemiology of louse infestations. In: Orkin M, Maibach HI, eds.
infestations and insect Bites. New York: Marcel Dekker, 1985: 187-98.
Jessup CA, Coll B. Pediculosis: the Philadelphia school problem.
Pediculosis corporis; an updating of attitudes. Environ Health 1983; May:
Burns DA. The
treatment of Pthirgus pubis infestation of the eyelashes. Br J Dermatol
1987; 117: 741-3.
Sperber J, Rosen T et al. Treatment of pediculosis pubis. Arch Dermatol
1987; 123: 13l5-19.
Pediculosis and the pediatrician. Pediatr Dermatol 1984; 2: 74-9.
Mckinsey JJ. Removing a tick. North Carolina Med J 1985; 46: 471.Dermatol
1981; 8: 157-9.
Heyl T. Tick
bite alopecia. Clin Exp Dermatol 1982; 7: 537-42.
Human ‘seed tick‘ infestation. Arch Dermatol 1981; 117: 812-14.
Polishing off ticks. New Engl J Med 1983; 309: 992.
Human ‘seed tick‘ infestation. Arch Dermatol 1981; 117: 812-14.
Sherman WT. Polishing off
ticks. New Engl J Med 1983; 309: 992.
DISEASES DUE TO FLEAS
The human flea is
worldwide , inhabiting cervices in floors , walls and furniture of houses,
sand or earth, and occasionally deposits eggs on clothing.
Fleas can cause
skin lesions such as macular, urticarial lesions with characteristically a
small punctate hemorrhage at the sit of bite.
many dangerous diseases such as Murine typhus, plaque, tularemia and others .
Fig. 141. Flea
Fig. 142. Insect bite (Papular urticaria)
is the most common skin manifestation of fleabites and varies according to
site, and age of the patient, and whether the skin is sensitized or not by
are not sensitized to the fleabite so the reaction is usually severe at
Young children are
mainly affected by urticarial lesions on the exposed areas of the face and
extremities. Papular, wheals and even bullous lesions appear in highly
sensitized individuals .
Later on when
sensitization occurs after the first attack the reaction is minimal and
may pass without notice as in adults who are usually exposed to repeated
steroid ointment .
Eradication of the
fleas from clothes and domestic animals as cats and dogs by spraying by
five percent DDT.
(Burrowing Flea )
female sand flea (Tunga penetrans) is the burrowing flea into the skin,
where most of her body is buried into the skin , while her posterior part
is apparent out. The female flea sucks blood and becomes huge in size.
Hard itchy nodule
appears at the site where the female buries itself into the skin of soles,
feet, ankles and interdigital areas. This may lead to pustular lesion that
may suppurate leading to an ulcer. The female flea may be seen as a dark
plug representing the posterior part of the female flea . More than one
pustule may be seen due to impregnation of the skin with more than female
flea. These lesions may coalesce together forming a boggy nodulo-pustular
If the burrowing
flea persists for a long time and not removed from the skin, this may lead
to deep and extensive ulcer, gangrene, lymphangitis, septicemia and rarely
this may be fatal.
Avoid walking barefooted. Use the
appropriate shoes .
Good hygiene of the feet .
Infested areas are
treated by D.D.T or Lindane or by fire to the site where the female flea
has burrowed the skin .
Gauze soaked with
chloroform or ether applied to the area may be enough to kill the flea .
The pustule is
opened and the flea is removed.
Oral and topical
antibiotic is needed to treat the pustules or the ulcers .
Flea bites and other diseases caused by fleas. In: Arthropods and Human
Skin. Berlin: Springer-Verlag, 1984: 159-71.
Chua EC, Goh
KJ. A flea-borne outbreak of dermatitis. Ann Acad Med Singapore1987; 16:
Campbell AR, Sayles PC. Human infestation by cat fleas; Ctenocephalides
(Siphonaptera: Pulicidae), from suburban Raccoons. J Med Entomol 1979;
16 (6): 547.
Miller WH. Flea infestation and its control. Int J Dermatol 1983; 22:
Stephens JH, Tschen JA. Tunga penetrans. Cutis 1988; 42: 47-8.
Tungiasis. In: Arthropods and Human Skin.
Springer-Verlag, 1984: 171-6.
Stephens JH, Tschen JA. Tunga penetrans. Cutis 1988; 42: 47-Sanusi ID,
Brown EB, Shepard TC et al. Tungiasis: report of one case and review of
the 14 reported cases in the United States. J Am Acad Dermatol 1989; 20:
DUE TO BUGS
Bed bugs suck
blood from their victims at night and hide during the day in clothes,
furnitures or on the floor. Bed bugs are available in crowded places such
as refugee camps, military camps and prisons. Bed bugs can cause skin
manifestations on biting the skin and are considered as vectors for
systemic diseases such as Trypanosomiasis .
Fig. 143. Kissing bug
Fig. 144. Insect bites (Papular & Papulovesicular lesions)
wheal with a central hemorrhagic punctum at the site of the bite. Itching
is not severe to wake the individual from his sleep and this why that the
bug takes its time easily to bite several areas.
In children the
reaction is more severe so that vesicular or bullous reactions occur at
the top of the wheal. The wheal does not last long, it may disappear after
a few hours although sensitization to bug saliva may occur resulting in
sensitization and eczematization.
The most common
sites involved are the neck, back, buttock, ankles and wrists. Secondary
bacterial infection is due to severe scratching and excoriation of the
Kissing bugs of the genus Triatoma
transmit Trypanosomiasis and cause skin manifestations characterized by
painful, pruritic papules, bullae and nodules .
bugs by spraying 5-10 % DDT to the places inhabited by bugs .
treatment for itching and secondary bacterial infection .
Museum (Natural History) economic series no. 5. The Bed Bug. London:
Trustees of the British Museum (Natural History), 1973.
Lyons SF. Experimental assessment of bedbugs (Clectularius and Cimex
hemipterus) and mosquitoes (Aedes aegypti formosus) as vectors of human
immunodeficiency virus. AIDS 1987; 1 (3): 171-4.
Manifestations Due to Beatles
Beatles may cause
skin irritation due to the Cantharidin present in their knee joints,
genitalia and prothorax . The beetles excrete this material only when
disturbed as by crushing or even slightest pressure when they are moving
on the skin .
Fig. 145. Beatle (With the sac on the joint)
Mild tingling and
stinging sensation at the site where the Cantharidin secreted from the
beetles becomes in contact with the skin. Later on a bulla may develop
after a few hours. More than one blister may occur, usually in one line and
appear may be seen next morning where the beetles usually wonders at night
. The parts involved are usually the exposed areas of the bodies as the
introduction of the eggs or larvae in traumatized skin, nasal, or ocular
cause cantheriasis with severe local manifestation as myiasis caused by
the fly larvae .
DISORDERS DUE TO SPIDERS
species of spiders may attack human beings causing skin
reactions due to their toxins . The most common of these is
the black widow and the brown spider . The yellow and
black garden spiders may cause sometimes tissue reaction but
less severe than the brown and the black widow.
Fig. 146. Brown spider
Fig. 147. Black widow
Black Widow Spider
spider is about one and a half centimeter in length with
long legs and has hourglass-like orange red markings, and
with a coral black color. The black widow usually bites when
skin manifestations may be minimal and usually not noticed.
Morbilliform eruption may be noticed in some cases .
severe constitutional symptoms may follow the bite due to
the spider toxins. These include severe pain at the site of
bite followed by chills, vomiting, cramps, delirium,
abdominal cramps and severe abdominal pain which may
simulate acute abdomen or food poisoning.
paralysis may accompany some cases especially in children .
brown spider has dark violin shaped band over the
cephalothoraxes and three pairs of eyes on the anterior
cephalothorax. This insect may cause more severe local and
systemic reaction than the black widow .
, chills, vomiting and joint pain.
hemolytic anemia and thrombocytopenia .
skin manifestations are usually severe at the site where the
insect attacked the skin.
extensive skin gangrene.
or morbilliform eruption.
Fig.146b. Brown spider bite
may develop surrounded by erythema and edema .
destruction and necrosis of the affected tissue, which is
usually at the site of genitalia, buttocks and limbs causing
severe agonizing pain .
ligature should be applied proximally to prevent spread of
the toxin to the circulation .
site attacked is incised to remove the toxins.
aid: suction of the area to remove the venom. Great care
should be taken that the mouth should be free from any
trauma or ulcer if suction was carried out by mouth .
is given if it is available .
injections by the intravenous or intramuscular route are
very helpful and may be life saving in severe cases.
gluconate intravenous is very helpful to relieve
methyl sulfate should be given to relieve muscle spasm
and abdominal cramps .
DISORDERS DUE TO BEES
bite human beings occasionally and usually when attacked or
disturbed. The female bees sting, which contains formic acid
and neurotoxin, by the ovipositor which is present on the
back of abdomen. The honeybee leaves its stinger into the
skin while the bumblebee is able to retract its stinger.
Fig. 148. Bee
severity or reactions elicited vary according to the age and
number of attacking bees and the site involved. This may be
severe which may cause anaphylactic shock and even death in
children or sensitized persons.
The local skin
reaction is mild or severe edema with burning and itching
accompanied usually by severe local pain. The reaction may
be more severe and edema extends to involve a wide area of
the adjacent tissue, which is red, swollen, tender and
measures in severe cases.
and antihistamine injections should be given in severe
if the stinger is still in the tissues, it should be
removed and great care should be taken to remove the sac
intact in order not to rupture where it may cause
dissemination of the toxins into the tissues. Sharp
scalpel may be used to gently scrap the sac or if
possible, pull the sac from the skin by the use of blunt
steroids may be needed to relieve the severe pruritus ,pain
MANIFESTATIONS DUE TO WASPS
may cause sever local and systemic reactions . Fatal cases
may occur due to neurogenic shock especially in infants and
young children .
Fig. 149. Wasp
types of wasps are known mainly the hornets, yellow jacket,
the hunting wasps and the social wasp .
reaction may be localized or systemic
papule or nodule with severe burning pain and itching.
Erythema and edema at the site of the sting may be severe
and extensive .
bacterial infection may complicate some cases with formation
of carbuncles or abscess at the site of the sting .
general collapse and that may lead to death .
removal of the venom sac.
of ice packs to minimize the reaction .
shock measures .
and calcium gluconate intravenous.
severe cases Epinephrine 0.3-.0.5 ml 1:1000 subcutaneous
and this may be repeated .
of severe cases may be necessary.
with alum -precipitated insect antigen for frequently
exposed individuals in areas inhabited heavily with
MANIFESTATIONS DUE TO ANTS
sting may cause mild or severe local reaction especially the
fire ants. Intense whealing and severe pain may follow the
and umbulicated pustules may be seen .
cases may need mild topical steroid .
- particularly in young children, systemic
corticosteroids and Epinephrine may be required .
Fig. 150. Fire
TI, Nicholls D, Holloway BA et al. Blister beetle
dermatosis in New Zealand. NZ Med J 1987; 100: 515-17.
MEC. Some observations on blister beetles, family
Meloid?, in Cambia, West Africa. Trans Roy Soc Trop Med
Hyg 1965; 59: 657-63.
DSH, Christmas TI, Greig DE. Oedemerid blister beetle
dermatosis: a review. J Ant Acad Dermatol 199O; 22:
MA. Insect bites and stings. Emerg Med Clin North Am
1985; 3 (4): 785-80.