Dermatology Flashcards
(180 cards)
1
Q
what are the diagnostic criteria for lupus?
A
Mucocutaneous:
- acute - photodistributed/sun-exposed rash
- chronic - alopecia
- Oral ulcers
- Alopecia
Synovitis serositis (pleuritis, pericarditis) Renal disease Neurological disorder Haemolytic anaemia, thrombocytopenia, leukopenia
Immunological: ANA anti-dsDNA, anti-Sm, antiphospholipid Low complement Direct coombs test
2
Q
What are the findings in cutaneous (discoid) lupus erythematosus?
A
discoid lupus erythematous
SCLE
3
Q
What are the cutaneous findings in systemic lupus erythematosus?
A
Alopecia Photodistributed rash Cutaneous vasculitis (manifesting as purpura) Chilblains Livedo reticularis Subacute cutaneous lupus
4
Q
In a newborn suspected of lupus, what test do you order? what are you testing for?
A
ECG - risk of heart block
5
Q
A _ is indicated as a test in SLE for renal function
A
urinalysis
6
Q
what are some symptoms of dermatomyositis?
A
Photosensitive erythema - usually scalp and periocular Shawl sign Heliotrope rash Gottron's papules Ragged cuticles
7
Q
Which antibody in dermatomyositis is associated with gottrons papules?
A
Anti Jo-1
8
Q
Which antibody in dermatomyositis is associated with interstitial lung disease and digital ulcers/ischemia?
A
Anti-MDA5
9
Q
Which antibody in dermatomyositis is associated with malignancy in adults?
A
Anti-p155
10
Q
Which antibody in dermatomyositis is associated with necrotising myopathy?
A
anti-SRP
11
Q
name 2 other antibodies in dermatomyositis
A
Anti-SAE - +/- amyopathic
Anti-p140 - juvenile, associated with malignancy
12
Q
what test are carried out if dermatomyositis is suspected?
A
Muscle biopsy - main test Autoantibody profile Skin biopsy LFT - ALT often increased Screening for internal malignancy
13
Q
State 3 conditions that can be associated with dermatomyositis
A
interstitial lung disease
digital ischemia
malignancy
14
Q
___Is a manifestation of small vessel vasculitis
A
purpura
15
Q
State 4 manifestations of medium vessel vasculitis
A
digital necrosis
retiform purpura and linear ulcers
Subcutaneous nodules along blood vessels
Livedo reticularis
16
Q
What are the symptoms and signs of IgA Vasculitis?
A
Skin - purpura on buttocks/legs
Arthralgias
GI - abdominal pain, meleana
IgA associated glomerulonephritis (hematuria, proteinuria)
17
Q
What are the symptoms/signs of Granulomatosis with Polyangiitis (GPA)
A
Upper respiratory tract - sinusitis, otitis media
Lower respiratory tract - hemoptysis, cough, dyspnea
Small vessel manifestation - purpura
Medium vessel manifestations
Pauci-immune glomerulonephritis
18
Q
__ is a systemic disorder most commonly affecting the lungs. Histology involves non-caseating epithelioid granulomas
A
sarcoidosis
19
Q
what are some symptoms of sarcoidosis
A
Dry cough, dyspnea
Lupus pernio - skin lesions on face
Erythema nodosum - inflammation of subcutaneous fat in legs
KEY findings = Hilar lymphadenopathy - CXR
Papules on skin
UGLIER = (uveitis), Granulomas, lupus pernio, interstitial fibrosis, erythema nodosum (RA)
20
Q
what is included in the diagnostic criteria for DRESS?
A
Fever
Lymphadenopathy ⩾ 2 sites, > 1cm
Circulating atypical lymphocytes
Peripheral hypereosinophilia
Internal organs involved - Liver most common(hepatitis)
Negative ANA, Hepatitis / mycoplasma, chlamydia
Skin involvement:
>50% BSA
Cutaneous eruption suggestive of DRESS e.g. facial oedema
Biopsy suggestive of DRESS
21
Q
how do you treat dress?
A
stop drugs, start corticosteroids
22
Q
What accounts for most fatalities in DRESS
A
fulminant liver failure
23
Q
signs and symptoms of shnitzler syndrome?
A
recurrent urticarial rash - resolves with brownish hyperpigmentation.
Recurrent fever above 40°C
Bone or joint pain (especially over the ilium or tibia)
Raised monoclonal IgM
Organomegaly - Lymphadenopathy, hepatomegaly or splenomegaly
Neutrophilia
Elevated acute phase reactants or abnormal bone imaging
24
Q
What is the treatment for schnitzler syndrome?
A
Mild - colchicine
Severe - anakinra
25
____ is a multiorgan disease affecting 10-80% of allogeneic HSCTs. It can cause a rash including face and acral involvement as well as GI effects (diarrhea, abdominal pain) and Liver effects (elevated bilirubin/jaundice, elevated LFTs)
Graft versus host disease
26
describe the pathophysiology of graft versus host disease
donor-derived T-lymphocyte activity against antigens in an immunocompromised recipient
27
Itching without a rash is known as___.
pruritus
28
name some causes of pruritus
```
Hematological causes: lymphoma, polycythemia - FBC, LDH, Ureamia - renal profile
Cholestasis - test LFTs
Iron deficiency or iron overload - test ferritin
HIV/Hepatitis A/B/C
Cancer
Drugs - opiates
Psychogenic
Pruritus of old age
(XR chest to check for lymphadenopathy)
```
29
____ ___ develops from constant rubbing or scratching in pruritus
nodular prurigo
30
___ ___ is a manifestation of plasma cell dyscrasia
systemic amyloidosis
31
What symptoms, excluding skin findings, are common in systemic amyloidosis?
Weight loss, Fatigue
**parasthesias - e.g carpal tunnel syndrome
**Dyspnea - restrictive cardiomyopathy - can progress to heart failure
Syncopal attacks
**hypertrophy of muscles - e.g macroglossia
32
Which investigations are carried out for systemic amyloidosis?
Biopsy of abdominal fat/rectal mucosa
| SAP scan
33
State cutaneous manifestations of systemic amyloidosis
Racoon sign - periocular purpura
Papules can also occur in other places - face, neck, scalp, anogenital region, digits
Skin involvement ONLY in 25% of cases
34
What are the symptoms of scurvy?
Spongy gingiva with bleeding and erosion
Skin - petechiae, ecchymosis, follicular hyperkeratosis
Corkscrew hairs with perifollicular hemorrhage
35
___ results from protein deficiency
kwashiokor
36
state some skin changes seen in kwashiokor
Superficial DEQUAMATION
Sparse, dry hair
Soft, thin nails
Cheilitis
37
state some systemic features seen in kwashiokor
```
Hepatomegaly
Bacterial / fungal infections
Diarrhoea
Loss of muscle mass
Oedema
Failure to thrive
```
38
In a Zinc deficiency, what triad is usually seen? When not acquired, what is the genetic cause of deficiency?
Dermatitis, Diarrhoea, Depression
| Genetic - SLC39A4
39
In what locations is dermatitis commonly seen in a zinc deficiency and what are some common cutaneous manifestations?
Perineal, perioral, acral
| Erythema, Scale-crusts, Erosions, Alopecia, Stomatitis, Conjunctivitis
40
state a role of zinc in the body
Wound healing, antioxidant
41
Severe deficiency of what vitamin leads to pellagra? What 4 “Ds” are seen in pellagra?
```
Vitamin B3 (niacin)
Diarrhea, Dermatitis, Dementia, Death
```
42
State some cutaneous manifestations of vitamin B3 deficiency
Photodistributed erythema/hyperpigmentation - classically dorsal surface of hands and on face
“Casal’s necklace”
Glossitis and cheilitis
Painful fissures of palms and soles
43
Flushing, diarrhea, difficulty breathing, hypotension are all signs of ____ ___ where 5HT is released into the bloodstream
Carcinoid syndrome
| Flushing only present in 25% of cases
44
What is the difference between SJS and TEN?
SJS affects < 10% of the body. TEN affects > 30. Overlap in between
45
What are the symptoms in SJS/TEN
Prodromal - flu like symptoms
Skin lesions - macules, erythema, blisters, atypical targetoid
Blisters merge and sheets of skin detach
nikolsky +ve
46
What is the main cause of SJS and TEN
drugs
47
What are the main complications of SJS/TEN?
Death - 30%
Dehydration
Blindness
eroded GI tract - ulceration, perforation
interstitial pneumonitis, renal tubular necrosis
Multiple organ failure - liver and heart failure
hypothermia/hyperthermia, neutropenia
48
What are some differentials for SJS/TEN?
Staphylococcal scalded skin syndrome (SSSS)
Thermal burns
Cutaneous graft versus host disease
49
__ is generalized erythema affecting >90% of BSA
erythroderma
50
What are the causes of erythroderma?
Drug reactions
Lymphoma - sezary syndrome
Skin conditions - psoriasis, atopic eczema
Idiopathic (25-30%)
51
State some complications of erythroderma
thermoregulatory problems
Protein and fluid loss
Sepsis risk
Tachycardia, peripheral edema
52
Prurigo means __ __
itchy spots
53
xerosis means _ __
dryness
54
___ is a condition where calcium blocks the arteries. Patients can get Retiform purpura and ulcers.
calciphylaxis
55
describe some cutaneous signs of CKD
Conjunctival pallor, hair thinning (anemia)
Excoriatons, Prurigo - high urea in the blood
Calciphylaxis
Half and half nails
Manifestations corresponding to underlying cause of kidney disease such as:
SLE
ANCA-associated vasculitis
Viral warts, skin cancer (immunosuppression following kidney transplant)
Nephrogenic systemic fibrosis
Xerosis
Perforating disorder
56
Describe some cutaneous signs of Chronic Liver Disease
```
Muehrcke’s lines
Terry’s nails (mostly white with distal dark band)
Jaundice
Spider telangiectasia
Palmar erythema
Porphyria cutaneous tarda
Clubbing
Excoriations, prurigo
```
57
_____ _____ can occur in the setting of Diabetes Mellitus . It is characterised by red-brown plaques with pale or atrophic centres. It is treated with __
Necrobioisis lipoidica
| steroids
58
State some cutaneous manifestations of diabetes
```
Terrys nails
Granuloma annulare
Xerosis
Xanthelesma & Xanthomata
Neuropathic ulcers
Acanthosis nigricans - dry dark patches of skin usually in armpits, neck, groin
Skin infections
```
59
Eruptive xanthomas are common in __
hyperlipidemia
60
Pretibial myxoedema is seen in what endocrinological condition?
Graves disease
61
Hyperpigmentation of skin and gums is seen in what endocrinological disorder?
Addisons disease
62
Acne can be a sign of which endocrinological disorders?
cushings
acromegaly
pcos
63
Cutis gyrata verticis can be a sign of which disorder?
Acromegaly
64
List of cutaneous signs of systemic disease - in this case signs of Immunosuppression:
```
Severe seborrhoeic dermatitis
Extensive viral warts
CMV ulceration
Eosinophilic folliculitis
Norwegian scabies
Bacillary angiomatosis
Severe psoriasis
Penicillinosis
Tinea corporis & faciei
Cryptococcosis
Kaposi sarcoma
```
65
what are the symptoms of HIV infection?
Seroconversion stage can get many types of rashes - ERYTHEMA MULTIFORME UTICARIA, MORBILLIFORM RASH, oral/genital ulceration
persistent or atypical manifestations of common infections
Severe manifestation of common dermatoses - e.g. psoriasis, seborrheic dermatitis
Itch
Eosinophilic folliculitis
66
State some cutaneous manifestations of inflammatory bowel disease
```
Pyoderma gangrenosum
Panniculitis (erythema nodosum)
Orofacial granulomatosis - lips, face or insides of mouth swell
Aphthous ulceration
Hidradenitis suppuritiva
Associated with psoriasis and pemphigoid
```
67
State some cutaneous manifestations of celiac disease
Dermatitis herpetiformis - itchy blisters of extensor surfaces
68
___ ___ causes inflamed nodes, abscesses, lumps in intertriginous zones, especially axillary anogenital and inframammary area
Hidradenitis suppurativa
69
State 3 causes of pyoderma gangrenosum
IBD, leukemia, seronegative arthritis
70
Groin metastases are common in __ carcinoma
prostatic
71
Which skin symptom can be a symptom of breast cancer?
Peau d’orange (breast location)
72
Name 5 skin infections that Staphylococcus aureus can cause:
Ecthyma
Impetigo
Cellulitis
Folliculitis ->abscess: furuncles, carbuncles
Staphylococcal scalded skin syndrome SSS
Can also superinfect other dermatoses (e.g. atopic eczema, HSV, leg ulcers)
73
Name 5 skin infections that Staphylococcus aureus can cause:
(Ecthyma, Impetigo, Cellulitis)
FOLLICULITIS ->abscess: furuncles, carbuncles
Staphylococcal scalded skin syndrome SSS
TOXIC SHOCK SYNDROME
Can also superinfect other dermatoses (e.g. atopic eczema, HSV, leg ulcers)
74
Name 5 skin infections causes by Streptococcus pyogenes
(Ecthyma, Impetigo, Cellulitis)
ERYSIPELAS
SCARLET FEVER
NECROTISING FASCIITIS
Can also superinfect other dermatoses (e.g. leg ulcers)
75
What enables staphylococcus aureus to infect wounds? Name one of its virulent exotoxins
Has receptors that allow it to bind to fibrin at wound sites (also in dermatitis)
Panton Valentine Leukocidin
76
Streptococcus pyogenes is ___ hemolytic. It has an __ protein along with hyaluronic acid __ which inhibit ___. It also produces ____ exotoxins.
```
B hemolytic
M protein
Capsule
Phagocytosis
Erythrogenic
```
77
What are the 2 main causes of folliculitis?
Infectious - S. aureus
| Non-infectious - eosinophilic folliculitis associated with HIV
78
How do you treat folliculitis?
Antibiotics, incision and drainage for furunculosis
79
What are the risk factors for recurrent staphylococcus aureus infections?
Abundant in nasal flora
| Immune deficiency - e.g. Diabetes Mellitus, AIDS, hyper IgE syndrome, hypogammaglobulinemia
80
Sign and symptoms of PVL staphylococcus aureus infection?
Recurrent and painful abscesses, Folliculitis, Cellulitis
MORE THAN 1 SITE, present in contacts
Extracutaneous:
NECROTISING PNEUMONIA
NECROTISING FASCIITIS
PURPURA FULMINANS
81
What are the 2 key effects of PVL toxin?
Leukocyte destruction and tissue necrosis
82
What 5 things increase your risk of PVL s.aureus infection
1. close contact
2. contaminated items
3. crowding
4. cleanliness
5. cuts and grazes
83
How do you treat a PVL s.aureus infection?
Antibiotics
Decolonisation:
- Chlorhexidine body wash for 7 days
- Nasal application of mupirocin ointment 5 days
Treatment of close contacts
84
What is cellulitis? What are the symptoms? What causes it?
Infection of DEEPER DERMIS and SUBCUTANEOUS tissue
Tender swelling, BLANCHING erythema, oedema, ILL defined
Strep pyogenes and S. aureus
85
What is impetigo? What are the symptoms?
Superficial skin infection = EPIDERMIS
Honey-coloured crusting
Usually affects face (perioral, nares, ears)
86
Differentiate between the different types of impetigo
non - bullous: caused by s pyogenes
Bullous: caused by s.aureus. Contribution of exfoliative toxin causes FLUID FILLED BLISTERS Toxin targets desmoglein 1.
87
In what setting does impetiginization occur? What causes it?
Atopic dermatitis
| S.aureus -> gold crust
88
What is ecthyma and how does it present?
Severe form of impetigo
Thick crust overlying a punched out ulceration surrounded by erythema
Usually on lower extremities
89
Which groups are susceptible SSS? And what causes it?
INFANTS & IMMUNOCOMPROMISED
Exfoliative toxin from s.aureus
90
What are the symptoms of SSS?
Infection occurs at distal site e.g. conjuctivitis
| Diffuse tender erythema -> flaccid bullae→ sloughing of intraepidermal layer of skin (no scar)
91
What are the symptoms of toxic shock syndrome?
Fever >38.9
Shock (hypotension)
Diffuse ERYTHEMA, erythema of mucus membranes (e.g EYES)
Organ involvement eg. liver
Hematologic (platelets <100 000/mm3)
DESQUAMATION predominantly of palms and soles 1-2 weeks after resolution of erythema
92
What causes toxic shock syndrome?
Exotoxin TSST-1 from s.aureus
93
How does Blistering Distal Dactylitis manifest?
1 or more tender superficial bullae on erythematous base on the volar fat pad of a finger
Toes may rarely be affected
typically young children
strep pyogenes or s.aureus
94
What are the symptoms of Erysipelas? What causes it?
Involves UPPER DERMIS
PAINFUL. Presents as erythematous SHARPLY demarcated plaque
FEVER (Malaise, fever, headache)
+/- SUPERFICIAL LYMPHATICS and BLISTERING
Strep. Pyogenes
95
What are some symptoms of scarlet fever? What causes it?
Fever, sore throat, headache. Blanching, sandpaper-like body rash
UPPER RESPIRATORY TRACT INFECTION with erythrogenic toxin-producing Streptococcus pyogenes
96
what are some complications of scarlet fever?
otitis, mastoiditis, sinusitis, pneumonia, myocarditis, hepatitis, meningitis, rheumatic fever, acute glomerulonephritis
97
Necrotising fasciitis is usually ___ or involves ____ as the only bacteria. Treatment is broad spectrum antibiotics and ___ ____
Polymicrobial (often anerobes)
S.pyogenes
Surgical debridement
98
What is the condition called when necrotising fasciitis spreads to scrotum?
Fournier's Gangrene
99
Cutaneously, how does anthrax manifest? What bacteria causes it?
PAINLESS necrotic ulcer with surrounding oedema and regional lymphadenopathy (with PAIN in lymph nodes)
Bacillus anthracis.
100
Cutaneously, how does erythrasma manifest? What causes it?
Well demarcated patches in intertriginous areas. initially pink -> Become brown and scaly
Infection of Corynebacterium minutissimum
101
Cutaneously, how does pitted keratolysis manifest? What causes it?
Pitted erosions of soles
Caused by Corynebacterium
Treated with topical clindamycin.
102
What Mycobacterium causes indolent granulomatous ulcers in healthy people? A risk factor is being an aquarium handler and has sporotrichoid spread?
mycobacterum marinum
103
What mycobacterium is an important cause of limb ulceration in Africa (Buruli ulcer) or Australia (Searle’s ulcer)?
mycobacterium ulcerans
104
Which two mycobacteria cause infection following puncture wounds, tattoos, skin trauma or surgery?
Mycobacterium chelonae & abscessus
105
Mycobacterium ____ is an obligate intracellular bacteria. It predominantly affects skin & nerves, but can affect any organ
leprae
106
Mycobacterium is a common cause of infection in __ states
immunosupressed
107
Distinguish between the two types of leprosy
Lepromatous leprosy:
Multiple lesions
Sensation and sweating normal (early on)
Tuberculoid leprosy:
- SOLITARY or FEW: elevated borders atrophic center, sometimes annular
- HAIRLESS, ANHIDROTIC, NUMB
108
Describe 3 ways that cutaneous TB may be acquired
Exogenously -> e.g. tuberculosis verrucosa cutis
Contiguous endogenous spread -> seen in scrofuloderma and periorificial tuberculosis
Haematogenous/lymphatic endogenous spread -> seen in lupus vulgaris, miliary tuberculosis, gummas
109
What diagnostic tests are useful for cutaneous TB?
Histology - ZN stain
culture/PCR
Interferon gamma release assay
110
What bacteria causes Erysipeloid? What is the typical exposure? What are the symptoms?
Erysipelothrix rhusiopathiae - after handling contaminated raw fish or meat.
Erythema and oedema of the hand
111
___ ______ is associated with hot tub use, swimming pools and depilatories, wet suits.
It appears 1-3 days after exposure, as a diffuse truncal eruption of erythematous papules. Usually self limited
Pseudomonal folliculitis -> caused by pseudomonas aeruginosa
112
The difference between ecthyma and ecthyma gangrenosum is that ecthyma gangrenosum is multiple ulcers, is caused by ___ ____ and usually occurs in neutropenic patients.
pseudomonas aeruginosa
113
What causes Tularaemia? What are the symptoms
Zoonotic bacteria: Francisella tularensis
Handling infected animals (squirrels and rabbits), Tick bites, Deerfly bites
PAINFUL ulcer and PAINFUL regional lymphadenopathy
Systemic symptoms: Fever, chills, headache, malaise
May have local cellulitis
114
what causes Lyme disease and how does the disease progress?
Bite form Ixodes tick infected with Borrelia burgdorferi
Stage 1 - flu like symptoms, erythema migrans (annular erythema/”bulls-eye”)
Stage 2 - secondary lesions, arthritis, cardiits, Neuroborreliosis (Facial palsy, Aseptic meningitis, Polyradiculitis)
115
What causes syphilis and what does primary syphilis look like?
Treponema pallidum
Chancre -PAINLESS ulcer. Classically on PENIS. + PAINLESS regional lymphadenopathy
116
What are the symptoms of secondary syphilis?
Maculopapular rash which also involves PALMS AND SOLES
Condylomata lata (painless, wart like WHITE lesions) - genitals, mouth, perineum
Small oral ulcers e.g. on tongue, mucous patches
Alopecia
Lymphadenopathy
Hepatospleenomegaly
117
symptoms of tertiary syphilis?
Gumma Skin lesions:
- plaques
- Extend peripherally while - central areas heal with scarring and atrophy
- Mucosal lesions extend to and destroy the nasal cartilage
Neurosyphilis - (general paresis or tabes dorsalis (broad-based ataxia))
Cardiovascular disease - stroke without hypertension
118
How do you treat syphilis?
IM benzylpenicillin or (oral tetracycline)
119
What is lues maligna? When does it typically occur?
Rare manifestation of SECONDARY syphilis
Pleomorphic skin lesions with pustules, NODULES AND ULCERS with necrotising vasculitis
More frequent in HIV manifestation
120
Differentiate between how the 2 types of herpes simplex viruses are spread
HSV1 - saliva, secretions
| HSV2 - sexual contact
121
What are the symptoms of a herpes simplex virus infection?
Tingling in the area, grouped blisters, crusting and resolution, can be asymptomatic
Latent, can reactivate
122
How does eczema herpeticum manifest? What causes it?
Cluster of itchy blisters/punched out erosions
often seen as a complication of atopic dermatitis/eczema.
Caused by HSV1 or HSV2
Emergency - can complicate into encephalitis
123
What is herpetic whitlow?
Pain, swelling of digits
| HSV 1>2
124
How does herpes gladiatorum manifest?
HSV 1 involvement of cutaneous site reflecting sites of contact with another athlete’s lesions
Contact sports e.g. wrestling
125
What causes neonatal herpes? What is a major complication?
Herpes simplex virus exposure during vaginal delivery
| Encephalitis (seizures, poor feeding)
126
How do you diagnose herpes simplex virus infection?
Swab -> PCR
127
How do you treat HSV infection?
Oral acyclovir or valacyclovir
128
How does a Varicella zoster virus reactivation present cutaneously? Feared complication?
single or multi dermatomal lesions
Complication -> blindness
Caused by HHV-3
129
What causes Roseola infantum? How does it manifest?
HHV6 and 7 in children
High fever -> followed by diffuse macular rash spreading from trunk to extremities
Self-limited
130
What causes Moloscum contagiousum? And how does it manifest?
Poxvirus
| Flesh-coloured papule with central umbilication
131
What causes Erythema infectiosum? How does it manifest
parvovirus B19
Slapped cheeks rash in children for 2-4 days
Then reticulated (lacy) rash of chest and thighs in 2nd stage of disease
132
What causes Orf? How does it manifest?
Parapoxvirus. Direct exposure to sheep or goats
Dome-shaped, firm bullae that develop an umbilicated crust.
Usually develop on hands and forearms
self-limited
133
What organisms cause warts?
hpv
134
What causes hand foot and mouth disease? How does it manifest?
coxsackie virus or echovirus (higher incidence or neurologic complications)
Vesicles, macules on buccal mucosa, tongue, palate and pharynx
Also on hands and feet
135
Other than drugs, which viruses cause morbilliform (measles-like) eruptions?
Measles, Rubella, EBV, CMV, HHV6 & HHV7 cause morbilliform (measles-like) eruptions
Leptospirosis
Rickettsia
136
Causes of petechial/purpuric eruptions?
Coagulation abnormalities - TTP, ITP, DIC
Vasculitis
Infections
Viruses - (Hepatitis B, CMV, Rubella, Yellow fever, Dengue fever, West nile virus)
Bacterial (BREN) - (Borrelia, Rickettsia, Neisseria, Endocarditis)
Other infections - (Plasmodium falciparum, Trichinella)
Other - (TEN, Ergot poisoning, Raynauds)
137
How does Gianotti-Crosti Syndrome manifest? What causes it?
Eruption of papules on the outer extremities in a symmetrical pattern
Some Viruses. It is self-limited
138
What causes Pityriasis versicolor? How does is it present?
Malassezia spp. Hot humid weather
| Hypopigmented, hyperpigmented or erythematous macular eruption +/- fine scale
139
How do you treat pityriasis versicolor?
topical azole
140
___ are fungi that live on keratin. Trichophyton ____ causes the most fungal infections
Trichophyton ____ causes the most tinea capitis
Dermatophytes
Rubrum
Tonsurans
141
Trichophyton tonsurans which causes the most tinea capitis can manifest with ___ formation. Tinea capitis is also associated with ___
Kerion
| Lymphadenopathy
142
Tinea unguium is also known as ___
onychomycosis
143
Describe the different ways in which tinea pedis can manifest
Interdigital
| Diffuse scaling of plantar surface of foot
144
what are id reactions?
Aka Dermatophytid reactions
Inflammatory reactions at sites distant from the associated dermatophyte infection
May include urticaria, hand dermatitis, or erythema nodosum
Likely secondary to a strong host immunologic response against fungal antigens
145
Follicular abscess produced when dermatophyte infection penetrates the follicular wall into surrounding dermis is known as?
Majocchi granuloma
146
Name a condition that predisposes someone to candidiasis. Describe how the condition presents
Diabetes mellitus
| Erythema oedema + discharge. Usually an intertriginous infection
147
Give examples of deep fungal infections and identify how they appear
Sporotrichosis - along lymphatics. Caused by sporothrix schenckii and other fungi
Chromomycois
Mycetoma (Madura foot)
148
Name 4 different systemic fungal infections and identify how they appear
```
Histoplasmosis
Blastomycosis
Coccidiodomycosis
Paracoccidoiodomycosis
(also penicillinosis)
```
149
What causes aspergillosis? How does it present?
Aspergillus fumigatus - RESPIRATORY pathogen. Septate hyphae that branch at 45 degrees
Papules with NECROTIC base and surrounding halo (a differential in necrotizing lesions)
May invade blood vessels causing thrombosis and infarction
May extend into cartilage, bone and fascial planes
150
What causes mucormycosis and what is the main risk factor for this condition?
Mucor and Rhizopus spp. (and others)
| DKA
151
How does mucormycosis present? How do you treat it?
```
Fever, headache
Facial oedema, facial pain
Orbital cellulitis
Cranial nerve dysfunction
Proptosis
Treat with debridement and antifungals
```
152
What are some opportunistic fungal infections causing skin disorders?
Candidiasis
Aspergillus fumigatus
Mucor and Rhizopus
Sporothrix schenckii
153
what are the symtoms of scabies?
red to flesh-coloured pruritic papules
Affects interdigital areas of digits, volar wrists, axillary areas, genitalia
diagnostic burrow consisting of fine white scale is often seen
Norwegian scabies immunocompromised
154
how do you treat scabies?
permethrin, oral ivermectin
| Two cycles of treatment are required
155
Distinguish between the different types of lice infestation
Head louse:
Pediculus humanus capitis
- Treatment: malathion, permethrin, or oral ivermectin
Body louse:
Lives and reproduces in clothing – leaves to feed; rarely found on skin
Pruritic papules & hyperpigmentation
Eliminated through cleaning or discarding clothes
Pubic Louse:
Phithrus pubis aka crabs; three pairs of legs
Eggs found on hair shaft, also found in occipital scalp, body hair, eyebrow and eyelash, axillary hair
Treatment: malathion / permethrin, oral ivermectin
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What are Cimex lectularius and what do they cause?
Bed bugs -> bites -> itchy weals around central punctum
157
What is the most common skin cancer? What is the second most common ?
Most common - basal cell carcinoma
| Squamous cell carcinoma
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What is a melanoma?
Malignant tumour of Melanocytes
| High metastatic potential. >75% of skin cancer deaths
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How does a melanoma present/look?
A - asymmetrical
B - border irregularity
C - colour variation
D - diameter >6mm
E - evolution - change in size, shape, colour
Can arise on mucosal surfaces too e.g. oral, conjunctival vaginal
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What are risk factors for a melanoma?
Genetic factors:
Family history - CNKN2A mutations, MC1R variants
Light skin
Red hair
DNA repair defects - xeroderma pigmentosum
Environmental
Sun exposure
Immunosuppression
Phenotypic
>100 or atypical nevi (ugly duckling sign) NOT just presence of nevi
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What are the subtypes of melanomas? What are the key features of each?
Superficial spreading
Most common - can be identified using ABCDE
Initial horizontal growth then vertical
Regression visible as grey, hypo- or depigmentation
Nodular
2nd most common
blue/black, sometimes pink
Aggressive.Develops rapidly - only vertical growth. LACKS RADIAL GROWTH
Lentigo maligna
Lentigo maligna = Brown to black macule with colour variation. Slow growing. Only 5% become invasive -> lentigo maligna melanoma
Sun damaged skin - usually face
Acral lentiginous
least common
Occurs on palms and soles (can appear ulcerated, scaly) and nail apparatus
Affects all skin types equally. Higher proportion than other types of melanomas in african-americans and asians !!!!!
Unclassifiable
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What signalling pathway regulates cellular proliferation, growth and migration? What mutations in this pathway result in Melanomas?
Activation of MAPK pathway:
- KIT mutations (seen in some acral and mucosal melanomas)
- Activation mutations in BRAF, NRAS
- Mutations in CDKN2A which encodes p16 (tumour suppressor gene)
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____ is a natural inhibitor of T-cell activation and prevents host immune response, leading to melanoma development. Immunotherapy is based on blocking it. Name a drug used for this
CTLA-4
| Ipilimumab
164
Other than CTL4-A inhibitors, what other drug is used in immunotherapy for melanomas?
Checkpoint inhibitors - PD-1, PDL1 inhibitors (nivolumab)
165
What investigation is carried out for suspected melanoma?
Dermoscopy. Should not be considered in isolation. If in doubt/ suspected melanoma-> excise with wide margins
166
What stage of melanomas is sentinel lymph node biopsy offered for?
pT1b +
167
What blood component is a prognostic factor in metastatic melanoma?
LDH
168
State 4 conditions that can result from keratinocyte dysplasia/carcinoma
Actinic keratoses -> can lead to squamous cell carcinoma. But LOW risk
Squamous cell carcinoma (potential for metastases)
Browns disease -> squamous cell carcinoma in situ
Basal cell carcinoma (invasive but RARELY metastasize)
169
What are some risk factors for keratinocyte carcinomas ( more common in MEN)?
```
Organ transplantation (immunosuppressive drugs)
Chronic non-healing wounds
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170
How does actinic keratoses look/present
Erythematous or brownish papules/plaques
Or hyperkeratosis or both
Confined to epidermis
171
How do you treat actinic keratoses & bowens disease?
5-fluorouracil cream, cryotherapy, Imiquimod cream
Photodynamic therapy, curettage and cautery.
Excision
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How does a squamous cell carcinoma look/present?
Red/skin colour plaques - may ulcerate and produce keratin, crust or bleed
May be Papules, may be exophytic(sticking out)
Commonly on face, lower lip, ears, hands
Common in immunosuppressed
173
___ are dome-shaped nodules, they grow rapidly and spontaneously regress. They are a variant of SCC and commonly occur on face/sun exposed areas
Keratoacanthoma
174
What are the main subtypes of basal cell carcinoma? What are the key features of each?
Nodular
Most common
Shiny pearly papule, blood vessels
Superficial
Erythematous plaque
Morphoeic
Slightly elevated or depressed area. Resembles a scar
More aggressive behaviour - local destruction
Infiltrative - aggressive
Basisquamous
hyperkeratosis/scaling can be seen
Micronodular
More destructive than nodular
175
What are the 2 most common cutaneous T-cell lymphomas ? typically affect older adults
mycosis fungoides - common. 50% of primary cutaneous lymphomas
Sezary syndrome - rare
Typically affect older adults
176
What are the features of mycosis fungoides Hows do you diagnose it?
Erythematous, scaling patch sage -> Plaque stage -> tumour stage
skin biopsy. may take years
177
What are the features of Sezary syndrome?
Erythroderma
Generalised lymphadenopathy
Presence of neoplastic T-cells (Sezary cells) in the skin, lymph nodes and peripheral blood
178
How do you treat sezary syndrome?
Requires Systemic treatment
| Can also use Extracorporeal photopheresis
179
What causes Kaposi sarcoma? How does it appear? How do you treat it?
HHV8. endemic or related to immunosuppresion
pink-> dark violets patches, plaques, nodules, polyps
chemotherapy and/or radiotherapy, excision
180
What causes merkel cell carcinoma?
80% = polyomavirus
UV exposure
Does NOT arise from merkel cells but cells similar
