Schwarzenberger - Urticaria, Immunobullous, Purpura Flashcards
(110 cards)
1
Q
What is this?
A
- Urticaria: more of a blurred margin than in psoriasis plaques
- Should not generally see blisters, but you may see an extravasated blood cell
2
Q
What is urticaria?
A
- Rapid development of “hives”— evanescent (come and go in mins to hrs), itchy swellings of skin
- Inflam rxn in skin mediated by release of histamine (anti-histamine tx) and o/cytokines -> leakage from capillaries into dermis causing edema
- Allergic OR non-allergic in nature; lifetime prev of 20% -> may or may not have identifiable cause
- Wheals last a few hours before resolving; however, may get series of lesions over longer period of time
- May have associated angioedema (swelling of deeper dermis and subcu tissue) for up to 72 hours
3
Q
What are some of the associations with acute urticaria? Chronic?
A
-
Acute: <6 wks
1. Infections
2. Drugs: beta-lactam ABs, NSAIDs, aspirin, opiates, contrast media
3. Food
4. Inhalants
5. Stress
6. Systemic diseases -
Chronic: >6 wks -> majority no identifiable cause
1. Chronic infection
2. Rheum disorders
3. Auto-Abs to IgE receptor on mast cells
4
Q
What is this?
A
Angioedema
5
Q
What is angioedema?
A
- Occurs in 40% cases of urticaria in adults, and may be more frequent in food-induced urticaria
-
Typically involves face: lips, periorbital area, hands, and feet
1. Tongue, larynx, respiratory and GI tracts may be involved - Wheezing, difficulty breathing, abdominal pain, dizziness, low BP may be signs of anaphylactic rxn
-
Hereditary angioedema: rare condition with recurrent episodes of edema, abdominal pain
1. C1 inhibitor deficiency or dysfunction - Angioedema without urticaria often related to drug therapy -> ACEI’s
6
Q
What are physical urticarias?
A
- Forms of urticaria that are not immunologic and have a physical cause:
1. Dermatographism: response to scratching, rubbing, or stroking
2. Cold or heat urticaria
3. Delayed pressure urticaria: pressure sites
4. Solar urticaria: sunlight
5. Aquagenic urticaria: i.e., jumping into pool
6. Cholinergic urticaria: exercise, stress, and heat-induced
7
Q
How do you treat urticaria?
A
- Mainstay of treatment: antihistamines
1. Treatment must be ongoing
2. Prevents hives rather than making them resolve - May need several drugs or higher doses for chronic urticaria
- Other options: LT antagonists, H2-blockers
- AVOID SYSTEMIC STEROIDS: risk of rebound (only time these may be given is acute setting where pt took AB, and you knew this was the cause)
8
Q
What should you do if urticarial plaques last >24 hours?
A
- Consider possibility of urticarial vasculitis
- Biopsy is important to distinguish
9
Q
How common are cutaneous drug reactions?
A
- Cutaneous rxns to meds one of the most common dermatologic problems in hospitalized patients
1. 1-3% of inpatients experience a cutaneous adverse drug reaction - Many commonly used drugs have rates > 1%
- Many drug reactions are miserable; however, some are life threatening
10
Q
Who has increased risk of cutaneous drug reactions?
A
- Can happen to anyone, but increased risk with:
1. Increasing age
2. Female gender
3. Concomitant viral infections: EBV and HIV (e.g., you can get a rash when you give people with mono (EBV infection) penicillin)
11
Q
What are the common offenders in cutaneous drug reactions?
A
- Antibiotics
- Anticonvulsants
- Nonsteroidal anti-inflammatory drugs (NSAIDS)
12
Q
What are the most common cutaneous drug rashes?
A
- Variety of patterns, but:
1. 90% morbilliform or “maculopapular” rash
2. 5% urticarial - Morbilliform rash can be initial presentation of more serious rash, including toxic epidermal necrolysis, DRESS syndrome and serum sickness
13
Q
What is this?
A
- Morbilliform (maculopapular) rash: if you see this in a child, esp. if they are non-immunized, you should also think about measles
14
Q
What do you see here?
A
- Morbilliform drug eruption: multiple small, pink, itchy papules on trunk and pressure-bearing areas
- Spread over time to become confluent
- May be purpuric in dependent areas, esp. if pt is thrombocytopenic
15
Q
What is this rash? When will you get it?
A
-
Morbilliform drug reaction: usually starts 5-7 days after starting drug -> can also occur even a few days after drug is discontinued
1. Cell-mediated, T4 HS rxn -> have to become sensitized first, but this can happen during the drug course - Resolves spontaneously in one to two weeks, usually without complications
- Not uncommon to have sunburn-like peeling after resolution
- Anticonvulsants and ABs most common causes
16
Q
What are the most common causes of morbilliform drug reactions?
A
- Penicillins
- Cephalosporins
- Sulfonamides
- Anticonvulsants
17
Q
What is this? What are the most common causes?
A
-
Urticarial drug reaction: 2nd most common form of cutaneous drug reaction
1. Occur within minutes of exposure, and hives resolve within hours -
Most common causes:
1. Penicillins/cephalosporins
2. Aspirin
3. Latex
18
Q
What is an urticarial drug reaction?
A
- IgE-mediated, immediate hypersensitivity reactions (T1 HS)
- Requires prior exposure with antibody formation
- With re-exposure, antigen binds IgE on mast cells and basophils, inducing degranulation
19
Q
What is DRESS?
A
- Drug rash w/eosinophilia & systemic symptoms, aka, drug hypersensitivity syndrome
- Severe morbilliform drug reaction with eosinophilia and systemic illness (a little bit to very elevated IgE)
- Onset 2-6 weeks after exposure (happens late)
- Facial edema characteristic + fever, LAD, joint pain
1. Can be difficult to distinguish from viral infection - Multisystem involvement; liver common, and can be fatally involved (FULMINANT HEPATITIS)
- Persists weeks to months after drug stopped
20
Q
What’s up with this dude?
A
DRESS
21
Q
What drugs are most commonly implicated in DRESS? How is it treated?
A
- Drugs most commonly implicated:
1. Anticonvulsants
2. Antibiotics: sulfonamides, minocycline, erythromycin - Requires long-term treatment with corticosteroids
- Mortality up to 10% from fulminant hepatitis
22
Q
What is this? What are the common causes?
A
-
Fixed drug eruption: well circumscribed, red-brown plaque; often heals with hyperpigmentation
1. Recurs at same location following repeated exposure, and may blister
2. Commonly on genitals, lips, extremities -
Common causes:
1. Sulfonamides
2. NSAIDS
3. Laxatives
23
Q
What are SJS/TEN? Causes?
A
- Stevens-Johnson Syndrome/Toxic epidermal necrolysis: rare, but potentially life threatening spectrum of blistering skin diseases
- Precise pathophysiology unclear, but majority are drug-related
- Commonly implicated drugs:
1. Antibiotics: sulfonamides, penicillins, cephalosporins, quinolones
2. Anticonvulsants: phenobarbital, carbamazepine, lamotrigine
3. Allopurinol
4. NSAIDS (oxicam derivatives)
5. Nevirapine, Abacavir (HIV drugs)
6. Acetaminophen in children
24
Q
What is the difference between SJS and TEN?
A
- Considered a spectrum of same disease
- Skin and mucous membrane involvement usual in both
- Distinguished by % body surface area involved:
1.
- 10-15% BSA: overlap, and
- >15% BSA: TEN
25
When do pts get SJS/TEN? What happens?
- Onset _within 1-2 months of starting drug_
- Starts with influenza-like, febrile prodromal illness
- Mucosal irritation, conjunctivitis, dysuria common
1. _Mucosal involvement is hallmark_
- Skin *starts with morbilliform rash* or atypical, dusky _target lesions_ -\> may be painful or burning
1. Rash expands and skin starts peeling with _full-thickness loss_
- Multisystem involvement
26
What is this?
SJS/TEN (mucocutaneous involvement shown in attached image too)
27
What is going on here?
- Sloughing of skin in SJS/TEN
28
How do you manage SJS/TEN?
- **Critical step is identifying and stopping the offending drug**
- Patients need aggressive _supportive care_ -\> mgmt in burn unit appropriate where available
- Need for _multidisciplinary care_: skin care + specialty intervention for eyes, mucous membranes and OB/GYN
- High risk of infection -\> aggressive wound care
- **Treatment w/systemic steroids INC mortality**
1. Short window if you catch early where these might work as prevention
- Do NOT put these people on prophylactic ABs
- Use of IV immunoglobulin may have benefit
- _Mortality remains high_
- Typically heal up just fine, but may have some pigmentary changes
29
What is going on here?
- SJS/TEN: vaginal involvement
30
What are some examples of blistering conditions that are not autoimmune in nature?
- _Coma blister_: ischemic, pressure blister
- _Bullous impetigo_: from superficial staph or strep infections -\> can be pretty intense, and provoke biopsy for autoimmune disease
- _Edema blister_: from hydrostatic pressure alone
- Bullous smalll vessel cutaneous vasculitis
- Bullous fixed drug reaction
- _Exuberant bug bites in pts w/leukemia_: children with leukemia and adults with CLL -\> might help you pick up a leukemia
- Bed bug bites
- _Cutaneous mastocytoma_: localized collection of mast cells
- _Epidermolysis bullosa_: several different variations, but genetic and structural, not immunologic -\> babies who are born with eroded skin
31
What is this?
- _Coma blister_: ischemic, pressure blister
32
What is this?
- _Bullous impetigo_: from superficial staph or strep infections -\> can be pretty intense, and provoke biopsy for autoimmune disease
33
What is this?
- _Edema blister_: from hydrostatic pressure alone
34
What is this?
Bullous smalll vessel cutaneous vasculitis
35
What is this?
Bullous fixed drug reaction
36
What is this?
- _Exuberant bug bites in pts w/leukemia_: children with leukemia and adults with CLL -\> might help you pick up a leukemia
37
What is this?
Bed bug bites
38
What is this?
- _Cutaneous mastocytoma_: localized collection of mast cells
39
What is this?
- _Epidermolysis bullosa_: several different variations, but genetic and structural, not immunologic -\> babies who are born with eroded skin
40
What are the characteristics of the autoimmune bullous diseases as a group?
- Uncommon chronic skin conditions caused by _devo of auto-Abs_ against various skin proteins
- Usually affect _older individuals_
- Unknown etiology, but probs some sort of _epigenetics_ -\> genetic predisposition + an envo trigger
- Source of significant morbidity and, potentially, mortality
41
When should you suspect an autoimmune blistering disease?
- Patients with unexplained:
1. _Blisters_
2. Erosions on skin
3. _Erosions_ or pain in mucous membranes: can even be diagnosed by dentists due to mucosal lesions
4. _Itchy rash_ that doesn’t respond to “usual” treatments
42
What are the 3 autoimmune blistering diseases?
- Bullous pemphigoid and variants
- Pemphigus vulgaris and variants
- Dermatitis herpetiformis
43
What is epidermolysis bullosa acquisita?
- A less common autoimmune bullous disease with Ab’s to collagen 7 (affecting adherence of dermis to epidermis)
44
What is bullous pemphigoid?
- 4-14 cases per million/year; _women \> men_
- Affects older persons: age 68-82 or older
- Usually no obvious trigger, but rarely caused by medications
- Auto-Abs to hemidesmosomes in basal cells: target Ags are BP 180 and BP 230 proteins
- Tons of eosinophils is a hallmark (often line the BM even before blistering) -\> you can also get these with a drug reaction.
45
What is this?
Bullous pemphigoid
46
What do you see here?
- _Bullous pemphigoid_: separation of epidermis from dermis, with eosinophilic infiltrate
- Tons of **eosinophils is a hallmark** (_often line the BM even before blistering_) -\> you can also get these with a drug reaction
47
What do you see here?
- **Bullous pemphigoid**: IgG and C3
- _Remember_: the point of IF is to look for the characteristic Ab subtype (IgG, IgM, etc.).
48
What is this?
- _Bullous pemphigoid_: often starts with very itchy, urticarial rash
- May be confused for a drug reaction
49
What are these from?
- **Bullous pemphigoid**: blisters are tense and may or may not have surrounding erythema
- Usually _symmetrically distributed_: clue that this is not poison ivy
- Get _successive crops_ of these over periods of time
- Mucous membranes involved in less than 20%
50
What is this?
Bullous pemphigoid
51
What is this?
- **Mucous membrane pemphigoid**, a BP variant
- Scarring eye involvement; _can lead to blindness_
- Oral lesions
- +/- skin lesions
52
What is this?
Bullous pemphigoid
53
What is this?
- **Gestational pemphigoid** or “herpes gestationis,” a BP variant
- BP arising in pregnant women, usually _during 2nd trimester_
- Can be associated with preterm labor or low weight-for-gestational age baby
1. Mostly managed as high-risk OB pts
2. Baby can be born with some blistering too, but this is usually not long-term (from mom's IgG)
- Remits postpartum, but _can recur_ in successive pregnancies
54
How do you diagnose BP?
- **Skin biopsy** (from normal skin close to the blister) for routine studies and direct immunofluorescence (DIF) studies
1. DIF shows a _band of IgG and C3_ at the dermal-epidermal junction (see attached)
- May or may not find antibodies in the blood
55
What is the treatment for BP?
- Requires _long-term systemic steroids_ and/or immunosuppressive medications
- Usually lasts several years, then remits: not a lifelong disease, but can last 5-10 years
56
What is pemphigus vulgaris?
- Affects 1-10 per million worldwide
1. INC incidence in persons of Mediterranean or Ashkenazi Jewish descent
- Affects all ages; mean onset 50-60; _men = women_
- May have genetic susceptibility
- Auto-Abs to part of _desmosomes_: target Ag -\> **desmoglein 1 and 3**
57
Describe the histo and IF in pemphigus vulgaris.
- **Histology**: "row of tombstones”
1. Intraepidermal split (within epidermis)
2. _Acantholysis_: individual cells lose attachment
3. Basal layer (BM) stays intact
- **Immunofluorescence**: intercellular (netlike — b/t keratinocytes)
1. IgG and C3 -\> targeting desmogleins 1 & 3
58
What is this?
- **How pemphigus vulgaris starts**: clinically often starts with painful erosions in the mouth or gums
1. Can’t drink anything acidic, and can be very painful
59
What are the clinical manifestations of PV?
- Blisters may or may not be seen on skin
1. If present, blisters _flaccid and easily broken_
- Lesions most common on head, chest, back, and intertriginous areas -\> erosions can be painful
- _Mucous membrane involvement_ may be extensive, involving all mucosa, larynx, esophagus, conjunctiva (often starts here)
- Can get _scarring and conjunctival involvement_ (but not as bad as mucous membrane BP, which can lead to blindness)
60
How do you diagnose and treat PV?
- **Diagnosis**: skin biopsy (right at the edge, where there is active inflam, but still some skin), direct immunofluorescence
1. Can identify _circulating antibodies in blood_ almost always, and can follow serially to _assess disease progress_ quantitatively
- **Treatment**: needs long-term tx with steroids, immunosuppressives
1. Can be fatal without treatment—up to 70%
2. Rituximab has been used in some patients, stopping the disease before it even really gets started -\> this drug is unbelievably expensive
61
What are the 2 PV variants?
- **Pemphigus foliaceus**: superficial pemphigus
1. Antibodies _only against desmoglein 1_
2. Scale crusts resemble corn flakes
3. Endemic in _Brazil_; might be some infectious or regional trigger
- **Paraneoplastic pemphigus**: assoc w/ _malignancy_
1. Severe and recalcitrant mucosal involvement
62
What is dermatitis herpetiformis?
- Autoimmune bullous disease _linked to celiac disease and dietary gluten_
- Thought to be immunologic response to chronic stimulation of gut mucosa by dietary gluten in pts with genetic predisposition to gluten sensitivity
- Pts develop IgA Abs to tissue transglutaminase (t-TG) (in gut), and _t-TG cross reacts with epidermal transglutaminase (e-TG)_ in skin
63
What are transglutaminases?
- Cytoplasmic Ca-dependent enzymes that _catalyze crosslinks between glutamine and lysine_
- Important in forming insoluble protein polymers – _necessary to create barriers_ and stable structures, including blood clots, hair, skin
64
How is DH related to celiac?
- Patients with both celiac disease and DH have _gluten-sensitive enteropathy_
- Autoimmune targets in two diseases are subtly different, but _antibodies cross-react_
1. DH antigen = epidermal transglutaminase
2. Celiac disease antigen = tissue transglutaminase
- _Not all patients with celiac disease have DH_, but all DH pts are assumed to have enteropathy
65
Who gets DH?
- Average age of onset between 30-40
- _Men \> women_
- Genetic predisposition: assn with **HLA-DQ2 and HLA-DQ8**
- _History of GI symptoms_ common: ranges from cramping and gas to diarrhea
66
How do DH patients present?
- Pts present with _intensely itchy rash_; may or may not see vesicles
- _Distribution symmetric_: elbows, buttocks, knees, scalp and neck
- Mucosal involvement very rare
67
Describe the histo and IF in DH.
- _Histology_: neutrophilic, eosinophilic infiltrate at dermal papillae
1. Neutrophilic abscesses
- _Immunofluorescence_: granular **IgA and C3** in dermal papillae
68
What is the tx for DH?
- Strict adherence to a _gluten-free diet_ is key to management of both the gut and skin diseases
1. Gluten is what stimulates the inflammation
- _Dapsone_ can control the itch very dramatically, but doesn’t treat the gut (itch can be very bad)
1. Inhibits bacterial synthesis of dihydrofolic acid, but mechanism not well understood
- Association with o/autoimmune conditions, incl thyroid disease, diabetes, CT diseases
- _Some increased risk of lymphoma_ in the gut, so want to get chronic inflammation under control
69
What are purpura? What are their main causes?
- Non-blanchable, pink to purple macules/patches or papules _caused by extravasated red blood cells_ in skin or mucous membranes
- “Blood under the skin”
- Caused by:
1. Coagulation / clotting abnormalities
2. Leaky or abnormal blood vessels
3. Other causes, including trauma
70
What type of purpura is this? Be specific.
- **Non-palpable purpura**
- _Petechiae_: small, \<3 mm red or purple dots
1. Usually on dependent areas of body
2. Generally painless
- Spots don’t blanche, so there are extravasated blood vessels in the skin
71
What are the two categories of purpura?
- _Macular/non-palpable_ purpura: generally non-inflammatory
- _Palpable_ purpura: sign of vascular inflammation (vasculitis)
72
Who is more likely to have petechiae?
## Footnote
* A patient with hemophilia
* A patient with cancer receiving chemotherapy
Patient with cancer receiving chemotherapy bc they are likely to have LOW PLATELETS
73
What are the two types of causes of petechiae?
- _Platelet related_: low platelets or platelet dysfunction
- _Non-platelet related_: things that increase capillary fragility or allow them to leak
74
How can scurvy cause this?
- Need Vitamin C to maintain integrity of capillaries
1. Remember: petechiae can be a result of platelet problems OR things that INC capillary fragility
- Petechiae almost always around hair follicles in scurvy
1. Get corkscrew hairs too, and easily bleeding, pliable gums
75
What are ecchymoses? What generally causes these?
- Larger, non-palpable areas of purpura (\>5 mm)
1. More likely reflect _ABNORMALITIES IN COAGULATION_, rather than platelet defects
a. Can be hyper-or hypocoagulable -\> too much bleeding or too much clotting
2. Can get both platelet and bleeding abnormalities, but simplified for learning
- Can be on any areas of body
- May/may not be painful, tender
76
What are some of the multifactorial causes of purpura?
- Thrombocytopenia + infection, inflam, trauma
- Abnormal PLT function + infection, inflam, trauma
- Infection
- _Anticoagulant + trauma_: DIC, renal or hepatic dysfunction, anticoagulant medications, Vitamin K deficiency
- _Poor dermal support + trauma_: actinic damage, amyloid, steroid-induced atrophy, fragility syndromes- Ehlers- Danlos, trauma, scurvy
77
What is this?
- **Solar purpura**: due to sun damage
- Could be a complication of use of _topical steroids_ chronically
- See this in _older patients on their forearms_
78
What do you see here?
- **Multifactorial purpura** -\> thrombocytopenia + trauma
- Linear purpura (=vibex) on upper arm due to blood pressure cuff in thrombocytopenic patient
79
What is this?
- _Multifactorial purpura_
- Steroid-induced atrophy, actinic damage, trauma from pneumatic compression device
80
What are some of the common causes of petechiae?
- _ABNORMAL PLATELET FUNCTION_
- DIC and infection
- Increased intravascular pressure
- _Low platelets_: idiopathic, drug-induced (think cancer drugs), or thrombotic (autoimmune)
- Some inflammatory skin diseases
81
What are some of the common causes of ecchymoses?
- _COAGULATION DEFECTS_
- DIC and infection
- Trauma
- Skin weakness/fragility
- Waldenstrom hypergammaglobulinemic purpura
82
What is this?
Hypergammaglobulinemic Purpura of Waldenström
83
What should you think of right away when you see _palpable_ purpura?
Leukocytoclastic vasculitis
84
What are these?
- **Palpable purpura** in Henoch-Schönlein syndrome
- Syndrome in children (also adults) in which you get vasculitis associated with joint and abdominal pain
1. Often follows viral infection in kids (more benign)
2. Risk of kidney infection in adults
3. See IgA around the blood vessel
- Inflammatory things tend to have less sharp border
- _Cutaneous vasculitis can be seen in many settings_: malignancy, autoimmune, drug reactions
85
How are palpable purpura different than bland petechiae/ecchymoses?
- Associated with inflammation in the blood vessels
- Remember: no blood vessels in the epidermis
86
What do you see here?
Inflammation of the superficial vessels in HSP
87
What organs does vasculitis affect?
- Affects skin primarily and visibly
- Can affect vessels in other organs:
1. Kidneys
2. Lungs
3. CNS
4. GI tract
88
How are vasculitides classified?
- **Size of blood vessel** the primary determinant in classification of vasculitis
- Also determines what clinical findings we see
89
What are some diseases with small vessel vasculitis?
- Diseases with small vessel vasculitis:
1. Henoch Schönlein purpura (IgA vasculitis)
2. Infections
3. Drug reactions
4. Autoimmune diseases
5. Malignancy-associated vasculitis
6. “Idiopathic” / hypersensitivity vasculitis
90
What are these?
Palpable purpura from small vessel vasculitis
91
What do you see here?
- Palpable purpura from small vessel vasculitis
- Can get little erosions the further down you go into the skin
- The primary lesions are up higher, and the lower lesion is a secondary change
92
What do you see here? Why does it look like this?
- Small vessel involvement in a patient with Lupus
- _Thicker skin here, so less obvious vasculitis_
93
What happened here?
- Leukocytoclastic vasculitis in a patient with myelodysplasia
- Vasculitis can be a hallmark of progression to leukemia
94
What do you see here?
Meningococcemia (acute)
95
What are these? From?
- Palpable purpura from leukocytoclastic vasculitis
96
What do you see?
- Palpable purpura from leukocytoclastic vasculitis
97
What happened here?
- Vasculitis, like drug eruptions, affect dependent areas in hospitalized patient
- Always look at weight-bearing areas (pressure)
98
What are some causes of mixed size vasculitis?
- Mixed size (small and medium vessel vasculitis):
1. ANCA associated vasculitides
2. Churg-Strauss
3. Microscopic polyangiitis
4. Wegner’s granulomatosis
5. Cryoglobulinemic vasculitis
99
What could this be from?
- Mixed-size vasculitis: Churg-Strauss in this case
- May see nodules, ulcers (because vasculature further down in the dermis)
100
What are some medium and large vessel vasculitides? How can they affect the skin?
- _Medium vessel vasculitis_: polyarteritis nodosa
- _Large vessel vasculitis_:
1. Giant cell arteritis (doesn't really affect skin)
2. Takayasu arteritis (doesn't really affect skin)
3. Behcet’s: can cause ulcers
- Less palpable purpura, but other lesions like _nodules or skin ulcers_
101
How does the size of the blood vessel involved in a vasculitis affect skin manifestations?
- _Small vessel = palpable purpura_
1. Blisters, less commonly hives
- _Medium vessel = nodules_, purpura, livedo reticularis/racemosa
1. Ulcers, skin necrosis
- _Large vessel = less likely to affect skin_
102
What does this IF stain show?
- IgA staining in HSP: notice the concentration around blood vessels (VASCULITIS)
103
What is this? What may have caused it?
- **Livedo reticularis from medium-size vasculitis**
- From polyarteritis nodosa, in this case (see attached image for histo)
- Not going to see palpable purpura necessarily, but see livedo (_vascular network in the skin enhanced due to stasis of the blood vessels_)
- Venous congestion, and also _small nodules_ here
104
What type of skin manifestation might this cause?
- **Livedo reticularis from medium-size vasculitis**: vascular network in the skin enhanced due to stasis of the blood vessels
- Can also small nodules here
105
What are the scariest form of purpura?
Retiform purpura
106
What are retiform purpura?
- A distinctive form of **ecchymosis with a “netlike” pattern** -\> caused by a variety of insults that interrupt blood flow to the skin
- Results from _vascular ischemia_, usually due to an underlying thrombotic (blood clotting) disorder
1. Congenital coagulation defects
2. Other acquired coagulation defects
3. _Infection_: ALWAYS presume this if the pt is ill and has a fever (until proven otherwise) bc could be disseminated sepsis
a. Skin biopsy can help determine this
b. MENINGOCOCCEMIA is among the most worrisome
- Widespread retiform purpura = _purpura fulminans_
107
What is this?
- **Purpura fulminans**: widespread retiform purpura
1. Ischemic necrosis following the vascular network
- From DIC, in this case
- Not round, not smooth -\> borders are very jagged
108
Are these bruises?
- NO
- Case from cocaine -\> predisposition to hyper-coagulation from a fungus (Levamisole) the drug is cut with (can recur)
- See attached histo image of THROMBOSES deep in the dermis
109
How does Warfarin cause a transient hypercoagulable state?
- Protein C and S deficiency first
- Followed by Vitamin K depletion of other clotting factors
110
What do you see here?
Histo of deep dermis thromboses (retiform purpura)
