Derm Flashcards
Key difference between tropical ulcer and Buruli ulcer? Who gets tropical ulcers? Usual bug?
Tropical are painful
Often - bacillus fusiformis
Poor and malnourished
[Buruli undermined border]
Cause of burili ulcer? What is it?
Mycobacterium ulcerans
slow-growing acid/alcohol fast bacilli
Usually following minor trauma and inoculation from stagnant water Eg rice farm
Buruli ulcer characteristic findings
Painless
Deeply undermined skin at edge
Often has satellite ulcers which communicate sub cut
Usually very invasive - osteomyelitis in 15%
Buruli ulcer ix? rx?
PCR assay - gold standard
– Direct examination
– Culture
– Skin biopsy (histopathology)
Rifampicin + clary (oral) OR streptomycin (IV) 8 weeks
AND surgical removal
Buruli ulcer control
BCG may offer some protection
Long trousers
education + early detection (painless so often delay in seeking rx)
What does myiasis mean? 3 main types? Which in Africa? South America?
Insect larvae invading sub-cut tissues or body cavities
Tumbu fly - Lies eggs on Ts - Africa
Bot fly - South America
Chiggers / jiggers - flea on feet you makes do jiggs
Tumbu fly other name? scientific name? Pathogenesis? rx? prevent?
Putzi fly - cordylobia anthropophaga
[Washing line cord]
Lies eggs on clothes on washing line
-> these hatche when warmed by body
-> causes a boil
rx is to suffocate using petroleum jelly and then remove larvae intact
Prevent by ironing clothes to kill eggs
Bot fly scientific name? Pathogenesis? rx?
Dermatobia hominis
[Makes a homis on your dermat]
Deposits eggs directly on skin -> boil lesion
Occlusion eg Jelly + surgical
[Not bad themselves but likely to get infected]
What causes cutaneous larva migrans? rx?
Hookworm - usually ancylostoma braziliense
Albendazole 400mg single dose
[or single ivermectin 12mg]
Compare rash from hookworm and from stronglyotides
Hookworm - cutaneous lava migrans - very slow moving 2-3mm per day.
-Very itchy and serpingous
Strongly- lava currens - faster moving and linear
Prevention cutaneous lava migrans
Footwear on beaches / parks
Ban dogs from beaches (from thier stool)
Dog de worming programmes
Scabies incubation for first infection
4-6weeks
Scabies rx best? cheapest? if severe crusting scabies in HIV?
All household treated and dose repeated after 1 week
Permethrin 5% 1st line
Benzyl benzoate 25% (not as good)
Ivermectin if really severe / in HIV
Name 2 species of louse? rx?
Body louse - Pediculus humanus
Pubic louse - Phthirus pubis
Head louse - pediculus capitis
Lotions with Malathion/permethrin / DDT
[can comb out head lice eggs]
Need to heat clothes after body louse to 70 degrees for at least 30 minutes
What is mycetoma (madura foot)? Key bugs
Chronic swelling with sinus formation discharging
Actinomycete bacteria
-Nocardia brasiliensis (south America)
-streptomyces somaliensis (Africa)
Fungus
-Madurella mycetomatis
[Less aggressive, fewer fistula and more slow growing]
Nocardia appearance? Whats interesting?
Rx?
Gram positive rods
form acid-fast beaded branching filaments (like fungi)
Co-trimox
[Bacteria acting like a fungi =antibiotic and anti fungal]
How do you get mycetoma? features?
usually from prick from a plant thorn
If on back -> often from carrying wood
Painless swelling
After several years break down to form discharging sinuses
With granules
Rx madurella mycetomatis? Actinomycotic bacteria?
Madurella mycetomatis- 1 year itraconazole / fluconazole
+surgery
Actinomycotic - co-trimox
+ streptomycin / amikacin / cef / linezolid / rifampin
[Second one based on drug sensitivities]
violet warty / ulcerated lesions which are itchy. Chestnut brown fungi or branching hyphae on smears =? cause? rx?
Chromoblastomycosis
Fungi from wood - enter through skin trauma
[Chromo colour from wood]
Rx tricky - combination eg itra + terbinafine
The treatment failure rate for leishmaniasis with SSG
25%
Malnourished kid with rapidlyprogressive mouth/cheek ulcerating disease is?
Noma
What is Splendore–Hoeppli phenomenon
Protinateous host response to foreign body
-Inflamm cells surrounding grain/cluster of bacteriaa
Fungal mycetoma is called
Eumycetoma
Which mycetoma has branching bacilli? rx
Nocardia (braziliensis)
3 weeks of co-trimox + amikacin
Then 22 weeks of co trimox + cycling other abx
Which mycetoma can you rx with surgery
Early lesions Eumycetoma
Lesions on kids face key Ddx in peru
Sporothrix schenckii
leishmaniasis
Why often cutaneous TB on Forearm or hands
Direct inoculation from coughing
Which lesions can follow lymph path ( sporotrichoid lesions)
Sporotrichosis
Leishmaniasis
Atypical micobacteria
Nocardiosis
TB
Other endemic fungi - histo, crypto, blasto
Pyodermitis
SLANT
Asteroid bodies on biopsy of cutaneous ulcer most likely
Sporotrichosis
If no hyphae or filamentous bacteria in mycetoma what do you suspect
Botryomycosis - s aureus
2 most common locations of Balamuthiasis
Face - often nose
Knee
Lesion on face especially with Painful ulceration in mouth Key Dx
Paracocci
If minimal oral involvement -> leish
lesion on face and nose with +++ necrosis
NK-T cell lymphoma (caused by EBV)
Painful ulcerations in mouth and anus
Parracocci
Herpes
Molliuscum-like lesions with hepatosplenomegaly and weight loss ? When else do you commonly get molluscum like lesions
Paracocci
Disseminated Cryptococcus Eg HIV
Molliuscum-like lesions with hepatosplenomegaly and weight loss ? When else do you commonly get molluscum like lesions
Paracocci
Disseminated Cryptococcus Eg HIV
Mpox
Talaromyces…
Eczematous lesions of the axilla, neck and head
Infective dermatitis
From HTLV-1
Which myiasis in Africa vs South America
cordylobia anthropophaga in Africa
Dermatobis homis in South America
Ulcer with amastigotes
Leishmaniasis
Buruli ulcer sx? Seen on biopsy?
- extensive, mostly painless very deep with undermined borders
- Acid-fast bacilli on edge of ulcer
Cause of chronic desert sore ulcer? Sx?
- Cutaneous diphtheria
Usually single, painful with adherent Slough
- Paralysis from toxin
Hypopigmented raindrop patches on trunk with minor scaling ?
Pityriasis versicolor
Chronic arsenic poisoning dermal presentation
- Slate gray colour of skin either small areas of normal skin
- Hyperkeratosis of palms and soles
Peripheral neuropathy
Raindrop appearance (white spots on darkened skin)
Name 2 causes of multiple painful genital ulcers
Herpes, chancroid (h ducreyi) , scabies
3 causes of multiple painless genital ulcers and bugs
- Syphilis t palladium
- Lymphogranuloma venereum - chlamydia trachomatis
- Granuloma inguinale - klebisella granulomatis
Anaesthetic lesions
Leprosy
Lesions on a childs face biopsy shows this
sporotrichosis
Mycetoma foot
Grains from mycetoma foot
Grains from mycetoma foot
Differential diagnosis of verrucous plaque
Chromoblastomycosis
Tuberculosis Verrucosa Cutis
Leishmaniasis
Sporotrichosis
Fusarium
verrucous nodules that are characteristically very slow-growing
Chromoblastomycosis
Verrucous leishmaniasis
Lesion of the central face?
Balamuthiasis
Balamuthia mandrillaris
Edema of the nose and upper lip, ulcerations in the mouth with haemorrhagic spots
Paracoccidiodomycosis
Central facial edema, mostly of the nasal pyramid and nasal cavity
Mucocutaneous leishmaniasis
Ulceration of the nasal pyramid and involvement of nasal
mucosa
With PROMINENT NECROSIS
NK T cell lymphoma of the nose
[EBV]
Swelling starts on forehead and works down
Rx?
Rhinoentomophtoromycosis
Zygomycetes infection eg Conidiobolus coronatus
Fluconazole/itraconazole
What is this lesion in TB called
Scrofula
Borderline leprosy
Leprosy
lives in Chicago
Comes to Lima with pulmonary disease and cold abscesses on the arms
North American Blastomycosis
Blastomyces dermatitides
Large painful ulcerations in the mouth and the anus with a cough
Paracoccidiodomycosis
systemic disease, hepatosplenomegaly, and moluscum like lesions
Juvenile or subacute form of Paracoccidiodomycosis
Umbilicated, moluscum like lesion in HIV
Cryptococcus
Painless ulcer what am i? describe?
Characteristics?
Cause?
Bururli - Ulcer with an undermined border (
massive necrosis and multiple bacilli
Mycobacterium ulcerans
Buruli distribution? Found where?
West Africa mostly especially ivory coast
[few in Australia and some in South america]
Around rivers and lakes especially stagnant water
M ulcerans pathogenesis - what must it have ?
Mycolactone toxin
-> causes destruction but also anaesthesia
-> Also immunosuppression
UNDERMINED borders
M ulcerans pathogenesis - what must it have ?
Mycolactone toxin
-> causes destruction but also anaesthesia
-> Also immunosuppression
UNDERMINED borders
Buruli always ulcer?
No may get nodules or plaques
Buruli on histology
Extensive fat necrosis
clumps of acid-fast bacilli on Ziehl Nielsen stain
Differentiate leish and buruli
Leish - raised borders, no undermining and minimal necrosis
Buruli - Undermined borders, extensive central necrosis
Oral Rx Buruli? common issue?
Rifampicin + clary (oral)
Paradoxical reactions may happen in up to
20% of cases
[Therapy diminishes the immunosuppression]
Buruli Size?
Amount of inflam infiltrate on histology?
How many mycobacteria ?
Other key features
- A large ulcer with undermined borders
- Extensive necrosis of fat
- Inflammatory infiltrate minimal or absent
- A-F stain with large amounts of bacilli ( only comparable to the amount seen in leprosy)
- Severely destructive, no inflammation, no pain, undermined borders
Why do kids get cutaneous TB chancre on their cheeks? What is almost also always there
Kiss from parents - lymphadenitis
Multibacilliary
What is a Scrofuloderma
Fistulous draining from underlying structure , such
a lymph node ,bone or epididymis
What are TB Gummas? Features?
Cold abscess as a result of hematogenous
spreading
-Necrosis predominates
-Granulomatous formation can be seen at the center
-Bacilli can be seen
What am I? Features?
Lupus vulgaris TB
Paucibacilliary
Usual on face - but also hands and feet
Well formed
granulomas , no necrosis
Tuberculosis verrucosa cutis differentiate from lupus vulgaris
The whole plaque is warty
Pathology is quite similar to lupus vulgaris other that facial
Bacilli not seen
Tuberculids are?
Ulcerated nodules, posterior aspect of legs
Lobular panniculitis
[Like erythema nodosum but ulcerate]
What type of TB am I?
Lichen scrofulosorum
Cutaneous TB rX?
RIPE - same as pulmonary
38M
Atrophy of the nasal mucosa and narrowing of the nasal cavity
Ulceration and infiltration of the hard palate mucosa
Biopsy demonstrates - this macrophage which has consumed bacteria =?
Caused by?
Rhinoscleroma
Klebsiella rhinoscleromatis
- rx tetracyclines
[Only found in people with genetic susceptibility]
3 phases
* Catarrhal phase
* Proliferative , granulomatous phase
* Sclerotic phase
Biopsy - Lymphocytes, plasma cells , histiocytes , PMNs and giant cells
Rhinoscleroma rx?
Cipro
2 cutaneous diseases caused by klebsiella?
Granuloma inguinale - klebsiella granulomatis
Rhinoscleroma - Klebsiella rhinoscleromatis
Granuloma inguinale also called? Rx?
Donovanosis
Azithromycin
Painful, rapidly growing , sloughing ulcer, usually on the leg
Mostly prevalent in tropical areas
Trauma always present , but can be trivial, from scratch to an insect bite =?
Usual cause?
Rx?
Tropical ulcer
Fusobacterium, commonly mixed with E. coli or Enterococcus sp.
Doxy + metronidazole
child with dental abscess which goes on to cause this? Associated with? Cause? Rx?
Noma
Chronic malnutrition, poor dental hygine
Fusiform bacilli + staph/strep
Penicillin + metronidazole
What It is the most benign form of endemic treponematosis, with clinical manifestations limited to the skin, including vitiligo like achromic lesions as well as hyperpigmented lesions? Found where?
What happens in late phase?
Pinta - Treponema carateum
South and central america
Achromic patches over body prominences after 2-5 years
Travel to South Africa and Botswana for safari
Tick bite which turned into image
->Fever malaise muscle pain = ?
Rx?
If there was a Triad of fever, eschar and rash which species?
African Tick bite fever - Rickettsia africae
Doxycycline
A disseminated rash is more common in cases
produced by R. conorii
Spontaneous abscess in large muscles of limbs / trunk with systemic symptoms
‘wooden’ texture =?
Usual cause?
Rx?
Tropical pyomyositis
Staph
IV Abx + drainage
rice farmer; works barefoo
10 year history of illness
tumor + fistula + grain discharge (black)
minimal pain initiall
no response to antibiotics
Dx?
Black grains = Madurella mycetomatis
Mycetoma Ix?
Visualise grains
Fine needle aspirate
US/ imaging
PAS / KOH staining
Molecular methods
Grain
Which cause of mycetoma may produce red grains ?
Actinomadura
Eumycetoma vs Actinomycetoma
World distrobution
Agressiveness
Fistula numbers
Sinus appearance
lymphatic spread
Size of grains
Medical vs surgical rx
2 most common causes of botryomycosis
Staphylococcus aureus (40%)
Pseudomonas aeruginosa (20%)
Agricultural worker with chronic (years) verrucous or vegetant (cauliflower) lesion =? Cause?
CHROMOBLASTOMYCOSIS
-trauma with wood or vegetation
Chonic lesion with black dots - on histology
Chromoblastomycosis
Chromoblastomycosis Rx
Cryotherapy / thermotherapy best
-Deep excision in early lesions
[Itraconazole + terbinafine]
fonsecaea pedrosoi
What am I ? Most common bug
Chromoblastomycosis
fonsecae pedrosoi
fon-sec-aea
[fon proSEC ae with Pedro]
Farmers / fishermen with a chronic keloid like lesion on ear / leg.
No black dots visulalied
Lobomycosis
Lacazia loboi
Chronic lesion
Histology round oval structures; 6 12um
in chains of 2 10 cells, connected by short tubular projections
Lacazia loboi (Lobomycosis)
Which vaccine should you check with myiasis
Tetanus
Inflammatory nodule with central crater on Soles/between toes, around toenails most likely? rx?
Tunga penetrans
[Itching helps to release eggs]
Extracted with a needle or scissors
▪ Prevention: Wear shoes, flea control
Tunga penetrans
Tunga penetrans
Name 2 causes of myiasis
Dermatobia hominis
Cordylobia anthropophaga
Cochliomyia hominivorax
Which fly classicly lies eggs in open wounds
Cochlyomyia hominivorax
Wound had this removed =?
Dermatobia hominis
“latigazo” is?
vesicular dermatitis caused by Blister Beetle
Paederus species
P. irritans , P. fuscipes, P. australis, P. melampus, P. brasilensis, P.colombius , and P. peregrinus
A lesion with a patent hole
Dermatobia hominis
For paederin to be produced what bacteria are required by blister beetles
Pseudomonas species
Only adult females produce paederin
Blister beetle Eg Paederus irritans
What are bed bugs actually called
Cimex lectularius
Flea bites are typically ?
In lines eg line of 3
especially bed bugs
Scabies real name
Sarcoptes scabiei
Sarcoptes scabiei burrows
Sarcoptes scabiei burrows
Sarcoptes scabiei burrows
What causes nodular scabies
Hypersensitivity reaction of the host by persisting mite antigens
Crusted scabies
Ivermectin
crusted scabies
Ivermectin
How do you confirm diagnosis of superficial mycoses
KOH stain
Tinea capitis
Single round patch of alopecia with scaling
Tinea capitis caused by? Rx?
microsporum canis
-Griseofulvin
Trichophyton tonsurans
-Terbinafine
Pityriasis versicolor
-Malassezia ssp
M furfur. M globosa and M sympodialis
Pigmented lesions on palms/soles
Tinea nigra
(Hortaea werneckii)
