CUTANEOUS INFECTIONS AND INFESTATIONS

Fahad Al Sudairy, M.D.

OBJECTIVES 1. General understanding of the causative

organisms of common skin infection(CSI).

2. Focus on CSI ( common skin infections ) clinical presentation.

3. Overview of the basic investigations done and general knowledge of first line therapy.

BACTERIA (impetigo , erysipelas &cellulits )

VIRUS (wart ,herpes simplex & herpes zoster)

FUNGUS (Tinea , candidasis)

PARASITE (Lieshmaniasis ,scabies & pediculosis)

BACTERIAL

The most common cause is Gram + ( like strept and staph )

Classification of skin infections according to the site : 1- superficial - Epidermis - ( ex Impetigo ) : and it

divided to : A-non follicular if the hair follicles are intact

(Impetigo)B- follicular if the hair follicles are involved (the

infection here is called folliculitis 2- deep infections – dermis - ( ex erysipelas &

cellulits ) )

I. Impetigo Superficial non-follicular infection due to

staphylococcus and streptococcus Children not sick ( No fever or any general symptoms ) pustule (honey-colored crust ) Face and Acral areas it could be :- Primary : if there are no previous lesions of the skin - or secondary : if the infection occur on previous

skin lesion (superinfection of severe ecsema “impetigo on top of ecsema”)

II. Erysipelas deep cutaneous infection (Dermal) due to streptococcus after penetrating trauma ( CHRONIC LYMPHEDEMA) sick ( the pt, come with fever , malaise and lymphoadenopathy ) Face and Acral areas ( unilateral ) Unilateral sharply demarcated edematous red plaque Prompt response to

full doses of oral peneicillin is the useful diagnosic test for erysipelasCHRONIC LYMPHEDEMA : ( repeated soft tissue infection lead to

damage lymph cause chronic lymphedema the lymphedema is perfect environment for infections ) So always treat the lymphoedema

III. Cellulitis deep cutaneous infection (up to SC FAT) due to streptococcus after penetrating trauma ( CHRONIC

LYMPHEDEMA) sick ( the pt, come with fever , malaise and lymphoadenopathy )

Face and Acral areas clinical presentation : Unilateral Diffuse (NOT well demarcated)

edematous red plaque always do Blood Culture in immuocompramized and Immunocompetent pts.

Rx : full doses of systemic antibioticsThe complications of soft tissue infections : 1- chronic lymphodema 2- septicemia

The clinical presentation difference between erysipelas and cellulitis is “the border”. Erysipelas affects the upper part of dermis, its border is clear and you can feel it without seeing! Cellulitis has no border, it’s diffuse and ill defined!

Viral Infection

Fahad Alsudairy , M.D.

VIRAL INFECTION1- WART (common benign self-limited cutanous tumors) causative agent : Human papilloma virus (HPV) , Separated by Direct contact Asymptomatic transmition ( at the transmission there are no any

symptoms the symptoms may appear later or they may never occur )

Delay in presentation (up to 10 years) Oncogenic potential (HPV 16 and 18) High recurrence rate ( because it is latent at the basal layer of the

skin )

HPV CUTANOUS ( HPV 1 and 3 ) common wart (found on the hands, in children 5-10

y/o, demonstrate the Koebner phneomenon)

flat wart

planter wart

GENITAL (HPV 6 and 11) :

classic

condyloma acuminata

Common warts

flat warts

Classic genetal warts

condyloma acuminata : elevated lesions ( more than 1 cm ) it look like papules

GENITAL WART

*they are the MOST COMMON STD

*it is Oncogenic HPVs ( Cervical cancer)

*Usually more persistent and difficult to treat .

If pt come with genetal Wart - always exam the whole genetoanal area- Investigate – analyze - the urine - Do serology for ( syphilis and the 3 H ( hepatitis – herpes

– HIV ) - Check the sexual partner

TREATMENT ( 2 methods : • Tissue destructive modalities • Keratolytic (salicylic acid and podophyllin) Cryotherapy ( Liquid nitrogen) Electrotherapy CO2 laser

* Immunotherapy

2- HERPES SIMPLEX

Causative agent : Human Herpes virus I and II

It separated by : Direct contact

Asymptomatic transmition

Latency ( delay presentation )

High recurrence rate

Type 2 virus has high association with cervical cancer

1 - CUTANEOUS ( HSV I - 98% of population ) Could be ( Initial Or recurrent ) orolibialis Initial Herpatic whitlow Recurrence( inflamation of the proximal nail folds – paronychia - )

herpes ophtalmicus RecurrenceOrbital infection

2- GENITAL ( HSV II )

Initial Recurrence

Incubation period : 7- 10 days. Presentation : After 24-48 hours of burning and tingling sensation the patient develop grouped vesicles on erythematous base which ulcerate within 24 hours. Hall mark

At presentation the pt usually have Erosions ( secondary lesions ) because the dz has fast progression .

The whole illness is around 7-10 days.

Topical steroid should not be applied to herpes simplex lesions

It appear as GROUPED infection

Investigations

1- Tzank smear

The Microscope will show ( Multinuculated Gaint cells ) This test not spesific to the type of the virus

2- Direct fluorescent antibody test very specific to the type of the virus

3- Viral culture

4- Blood serology used to check the partner

3- VARICELLAE ZOSTER VIRUS (VZV) Also called Human herpes 3

Transmission : Airborn ( respiratory droplets )

It cause :

CHICKENPOX ( Children)

HERPES ZOSTER (Adult) is due to reactivation of VZV which was dorminant in nerve root ganglion

A- CHICKENPOXIncubation period : 2 weeksPresentation : A- Prodrom of respiratory coryza ( Same

URTI ) followed by B- disseminated red macules with central

vesicles. ( in the Trunk sparing the Extremities )

The whole illness : 3 weeks The patient contagious 5 days before and 5

days after skin eruption

Classic presentation : red macules with central vesicles.

B- HERPES ZOSTERAfter 24-48 hours of burning and tingling

sensation the patient develop grouped vesicles on erythematous base which ulcerate within 24 hours.

The whole illness is around 7-10 days.

Post-herpetic neuralgia (PHN) which usually persist for around 4 weeks.

Types ( phases ) of Pain : 1- early : burning before the vesicles appear2- middle : tingling sensation when the visicles appear 3- late : Post-herpetic neuralgia (PHN) which usually persist for around 4 weeks after the vesicles Disappear . treat if it last longer than 1 moth

It usually unilateral and it is Dermatome ( follow the dermatome )

The commonest dermatomes : ( Spinal ( thoracic ) – Cranial (trigeminal )

It is almost always DERMATOMAL

SPINAL (Thoracic )

CRANIAL ( Trigeminal)

SERIOUS involvement1. Ophthalmic herpes :ex Ophthalmic division of

trigeminal nerve.

2. Risk of motor Nueropathy : ex Geniculate ganglia (Ramsey-hunt syndrome) which affect the External ear and it could cause Ipsilateral Facial palsy

3.Sacral ganglia.

4. Immunocomprimised Pt. : ex usually have Dissemanated Herpes

All these cases should treated by immediate IV antiviral ( acyclovir )

TreatmentHERPES SIMPLEX Acyclovir 200 mg five time a day for a

weekHERPES ZOSTERAcyclovir 800 mg five time a day for a

week

Molluscum Contagiosum

Poxvirus.

Dome-shaped pearly papuels with central umbilication.

Spontaneous resolution.

Treatment …

Fungal Infection

Fahad Alsudairy , M.D.

FUNGALTwo main groups :

1- DERMATOPHYTE 1- DERMATOPHYTE which cause :

A- Tinea Pedis (most common)

This Dz have many forms like :

1.Erosive interdigitalis

2. Hyperkeratotic type(T. rubrum) ( dry type ) this type trasfares from human to human ( anthrophilic )

3. Inflammatory type(T.mentagrophyte) ( wet type ) this type is Zoophelic

Tinea Pedis Inflammatory pedis

Tinea corporis / Tinea cruris 1.Hyperkeratotic type (T. rubrum) well-demarcated annular red

hyperkeratotic plaque with central clearing (Ring worm) classic pic

2.Inflammatory type (T.mentagrophyte) well-demarcated edematous red

plaque with superimposed pustules

well-demarcated annular red hyperkeratotic plaque with central clearing (Ring worm ) show central clearing Which type ?

Tinea Capitis ( affect the scalp ) 1.Hyperkeratotic (black dot) usually due to T. tonsurans2. Inflammatory (Kerion) how mycotic absess usually due to M. canis complex3. Favus * Due to T. schoenleinii * it characterized by the presence of

Scutulae ( golden crust ) .

1.Hyperkeratotic (black dot)

Inflammatory (Kerion) how mycotic abscess Show soft nodules and abcess

Favus : inflamed and eroded area

2- YEASTCandidosisDue to candida albicansIt is a commensal flora of the gut

which become pathogenic when the immune status of the person changed

When does it become pathological

physiological (old age , neonate and pregnancy)

pathological ( DM, HIV and organ transplant)

Itrogenic (long course of Antibiotics)

Locations

MUCOSAL

1. Oral

oral thrush

angular chilitis

2. Genital

valvuvaginitis

CUTANEOUS

it favor wet areas and the most common types are :

Candidal intertrigo

peripherally spreading glazed red patch with scaly border and satellite pustules

Candidal paronychia ( Nails )

It is weak organism So it affect the wet isolated areas only

Witch plaques on the tongue

2- pityriasis versicolor ( very common ) Due to Malassezia furfur ( previously

called : protrosposim oval )

Asypmtomatic

Well-demarcated brown patches with branny over the trunk and upper extremities

Well-demarcated brown patches with branny

Diagnosis

1. Scraping ,Clipping and Hair blucking

KOH/microscopy Culture

2. Skin biopsy Histopathology . ( Rare to be requested )

Treatment Topical Antifungal Nystatin preparation (oral thrush) for mucosal Candida Imidazoles e.g. cotrimazole and miconazoleSystemic AntifungalUse it for :- Tinea Capitis - onychomycosis (fungal nail infection) - Any Resistant infection Imidazoles e.g. Itraconazole and fluconazole Allylamine e.g. Terbinafine Griseovulvin

PROTOZOA

1- Lieshmaniasis

Protozoa called Lieshmania

Has 2 form :

At the Sand fly (premastigote )

At the Macrophage (Amastigote) it called Lieshman-Donovan bodies

Transmistion : sand fly

Presentation 1- Localized Cutaneous – most common Well-demarcated ulcerated nodule over the exposed

areas after a trip to an endemic area ( H/o of insect bite)

It caused by : ( L. tropical – L. major ) 2- Disseminated CutaneousNot localized Multiple non-ulcerated nodules Caused by : L. maxican 3- MucocutaneousCaused by : L. brazelai 4- Visceral ( kakazar )

Well-demarcated ulcerated nodule over the exposed areas ( classical presentation )

Investigations

Skin biopsy

Histopathology with Gimsa stain

Lieshman-Donovan bodies

Culture

PCR for DNA

Liesmanin test

Treatment

Resolve spontaneously leaving a scar

Antimony (Pentostam (( sodiume stepogluconate )) either Intralesional ( if localized ) or Intramuscular( if separated ) to shrink the lesion

2- Scabies Mite called sarcoptes scabei which residue in burrows in the

stratum corneum laying eggs then dieing and the eggs will maturate in 2 weeks period and the cycle repeated.

Skin lesions are Secondary eczematous eruption due to immune reaction to the mite and eggs

Show eczema only – no specific sign

When to suspect scabies ?

1.pruritus mainly at night

2. Other member of the family also having severe pruritus

3. Pruritus and skin eruption is more severe in the flexors

Document See the mite or eggs

Treatment

Permethrin cream ( 1st line )

Lindane cream

Malathion lotion

2.5% sulphur ointment

Instructions for treatment

1- treat all family members and close contacts even if they do not have symptoms

2- Do special cleaning for all the pt, ‘s belongs ( clothes and bed ) by Dry cleaning or bag it in well closed bag for 10 days

3- Use active treatment ( cover all the body specially the flexses ) put the cream and leave it for 24h then repeat it after 1 week to kill the eggs

3- PEDICULOSIS

Head lice (Pediculosis Capitis)

Children

Body lice (Pediculosis Corporis)

Homeless people and vagrants

Pubic lice (Pediculosis Pubis)

STD ( partner should be treated)

Diagnosis and treatment

The diagnosis can be conformed by seeing the lice eggs ( NITs)

Best treatment is SHAVING for head ( if boy ) and pubic lice. Alternatives:

Permethrin creame rinse ( 1st line )

Malathion lotion

Instructions for treatment

Ask the pt to use Permethrin Shampoo daily

Use special combs daily

Use active treatment- 1st line - ( for 24 h ) then repeat in 1 week

No need to treat the whole family

THANK YOU