Dermatology - Bright Red Rashes

From Iusmicm

(Difference between revisions)
(R5Wral Say, you got a nice article.Much thanks again.)
 
(3 intermediate revisions not shown)
Line 1: Line 1:
-
===Bright Red Rashes===
+
R5Wral Say, you got a nice article.Much thanks again.
-
*There are five primary players in bright red rashes:
+
-
**Urticaria
+
-
**Erythema multiforme
+
-
**Morbilliform eruptions
+
-
**Lupus erythematosus
+
-
**Dermatomyositis
+
-
 
+
-
====General tendencies====
+
-
*In general, vascular reactions to insult can be described by color, topography, and time course:
+
-
**Color: redness = erythema, results from excessive blood flow
+
-
**Topography: raised lesions result from edmea
+
-
**Time course: a reaction can be described as dynamic = evanescent
+
-
***Note that evanescent means "soon passing out of sight or memory"
+
-
*These three classic vascular reactions ('''erythema, edema, and evanescent''') best describe urticaria, erythema multiforme, and morbilliform reactions
+
-
 
+
-
====Urticaria====
+
-
*Urticaria is an '''allergic reaction''' that results in a bright red rash.
+
-
*Urticaria is colloquially known as "hives"
+
-
**The offending '''antigen is usually from a virus, a food, or a drug'''
+
-
**Physical factors can also induce urticaria (think "SPACE"): sun exposure, pressure, aquagenic, cold, exercise
+
-
*Pathogenesis of urticaria:
+
-
**Induction of immune response results in a dilated (erythema), leaky (edema) vascular state that can be readily changed (evanescent)
+
-
**Urticaria's EEE state is '''primarily driven by histamine''' acting on small dermal vessels
+
-
**'''Purpura can result if''' immune complexes damage endothelium to the extent that '''RBCs escape into the tissue'''
+
-
***Purpura generally lasts more than 24 hours at a single location
+
-
*The rash of urticaria is often described as being '''annular'''.
+
-
 
+
-
 
+
-
*http://www.urticare.com/site/urticare/images/basic_theme/back.gif
+
-
*http://images.paraorkut.com/img/health/images/u/urticaria-1944.jpg
+
-
*http://images.ddccdn.com/enc/images/images/en/hives-urticaria-close-up-1651.jpg
+
-
*http://www.rash-pictures.com/images/4/488.jpg
+
-
 
+
-
====Erythema Multiforme====
+
-
*Erythema multiforme is an '''allergic reaction''' that results in a bright red rash.
+
-
**Note that both urticaria and EM are allergic reactions.
+
-
*Erythema multiforme is distinct from urticaria by its '''immune complexes''' and its '''apoptotic cytotoxic T cells'''.
+
-
*Erythema multiforme is classified as minor and major based on how severe the manifestation.
+
-
**'''EM minor is usually caused by herpes simplex virus''', especially when EM is recurrent.
+
-
**'''EM major is usually caused by drugs'''
+
-
*EM Major has several named causes / syndromes: '''Stevens-Johnson syndrome''' and '''Toxic Epidermal Necrolysis'''
+
-
**Both SJS and TEN are (usually) allergic reactions to drugs that result in necrolysis of keratinocytes of the lower epidermis.
+
-
**Some consider TEN a more severe form or SJS.
+
-
*EM presentation:
+
-
**Target lesions on palsm
+
-
**Oral mucosal involvement
+
-
**http://medicalimages.allrefer.com/large/erythema-multiforme-target-lesions-on-the-palm.jpg
+
-
**http://im.unboundmedicine.com/medicine/ub/image?na=app:16010:ch18_8.bmp
+
-
**http://www.ebmedicine.net/media_library/aboutUs/Erythema%20Multiforme%20Pediactric%20Emergency%20Medicine%20Practice.JPG
+
-
**http://www.dermatopedia.com/wp-content/themes/dermatopedia/dermimages/4774_Erythema_Multiforme.jpg
+
-
**http://www.dermweb.com/hairnailsmucousmembranes/graphics/jpegs/Untitled-8a.jpg
+
-
**http://www.acponline.org/graphics/bioterro/e_minor.jpg
+
-
 
+
-
 
+
-
*Stevens-Johnson Syndrome images:
+
-
**SJS presents with '''widespread "targetoid" lesions'''
+
-
***Note that these targetoid lesions are different than the target lesions in classical EM presentation
+
-
**http://missinglink.ucsf.edu/lm/DermatologyGlossary/img/Dermatology%20Glossary/Glossary%20Clinical%20Images/Stevens_Johnson-28.jpg
+
-
**http://www.nursinghomesabuseblog.com/uploads/image/Picture%2023.png
+
-
**http://rad.usuhs.mil/derm/lecture_notes/Images/Stevens_Johnson.JPG
+
-
**http://img.medscape.com/fullsize/migrated/565/823/edm565823.fig2.jpg
+
-
**http://www.joeway.co.uk/images/stevenjohnsons2.jpg
+
-
 
+
-
=====Target lesions versus Targe''toid'' lesions=====
+
-
*Target lesions:
+
-
**Have '''concentric circles''', especially when there are three concentric circles
+
-
**Have central duskiness or a central blister
+
-
**Have a relatively wide pale circle in between
+
-
**Have an outer, thin, moderately erythematous circle
+
-
**http://www.aic.cuhk.edu.hk/web8/0024_erythema_multiforme.JPG
+
-
**http://dermgunner.com/wp-content/uploads/2010/09/target_lesions_of_erythema_multiforme.jpg
+
-
**http://images.medicinenet.com/images/image_collection/skin/erythema-multiforme-minor.jpg
+
-
**http://drugster.info/img/ail/2957_2979_1.JPG
+
-
**http://drugster.info/img/ail/2957_2979_3.jpg
+
-
**http://www.meddean.luc.edu/lumen/MedEd/medicine/dermatology/melton/erthmul1.jpg
+
-
 
+
-
 
+
-
*Targetoid lesions:
+
-
**Suggest zonality '''but don't have 3 distinct concentric circles'''
+
-
**http://upload.wikimedia.org/wikipedia/commons/thumb/6/68/EMminor09.JPG/230px-EMminor09.JPG
+
-
**http://dermnetnz.org/reactions/img/ermulti1-s.jpg
+
-
**http://dermatology.cdlib.org/1508/articles/2008102101/1.jpg
+
-
 
+
-
 
+
-
====Morbilliform Reactions====
+
-
*Morbilliform reaction is '''through to be a T-cell mediated hypersensitivity''' to drugs or pathogens.
+
-
*Etiology can be drugs or pathogens
+
-
**Many different drugs (including antibiotics) can cause morbilliform reactions
+
-
**Many pathogens can cause morbilliform reactions; usually enterovirus or group A streptococcus
+
-
*One diagnosis the etiology by culturing the "company" kept by the rash
+
-
*Morbilliform reaction manifests same symptoms regardless of causative agent
+
-
*Morbilliform reaction is '''less evanescent''' than multifomre erythema and urticaria
+
-
*Morbilliform reaction is characterized by '''truncal predominance'''
+
-
**Recall that urticaria could show up anywhere and multiform erythema usually involved the oral mucosa and palms of the hands
+
-
*Morbilliform is marked by its '''maculopapular rash'''
+
-
**Recall that a [http://editthis.info/iusmicm/Dermatology_-_Introduction#Macule_.2F_Patch macule] is NOT raised but is discolored and that a [http://editthis.info/iusmicm/Dermatology_-_Introduction#Papule_.2F_Plaque papule] IS raised but not necessarily discolored.
+
-
***http://www.aafp.org/afp/20000815/804_f1.jpg
+
-
***http://eso-cdn.bestpractice.bmj.com/best-practice/images/bp/en-gb/774-2_default.jpg
+
-
 
+
-
=====Viral Exanthems=====
+
-
*Most viral exanthems manifest as ''morbilliform reactions'' ('''except for varicella''').
+
-
**Recall that an exanthem is a skin eruption secondary to systemic disease.
+
-
**Recall that varicella is a viral infection with herpes.
+
-
*Recall the viral agents that cause the classic pediatric exanthems:
+
-
**'''These all cause MORBILLIFORM reactions'''
+
-
**Rubeola (Measles, paramyxovirus infection): cough, coryza, conjunctivitis, koplik spots
+
-
***Rubeola is a systemic infection by paramyxovirus of the genus Morbillivirus
+
-
**Rubella (German Measles, rubella virus infection): 3 day progression, progresses toward cephalocaudal poles
+
-
**Roseola (Roseola Infantum, roseola virus infection): fever, followed with '''rash when "defervesce"'''
+
-
**Mononucleosis: fever, fatigue, (f)pharyngitis, adenopathy, liver / spleen involvement
+
-
**Fifth disease (Erythema infectiosum): slapped cheeks, fishnet erythema, recurrence
+
-
***An example of "multiple stages" seen in many viral exanthems
+
-
 
+
-
 
+
-
*Viral exanthums are characterized by: "dew drop on rose petal" formation, umbilicated vesicles, and multiple stages:
+
-
**http://dermnetnz.org/img/umbilicated-s.jpg
+
-
**http://www.elsevierimages.com/images/vpv/000/000/037/37056-0550x0475.jpg
+
-
**http://203.64.79.70/DERMATOLOGY/fac/img0023.jpg
+
-
 
+
-
====Lupus Erythematous====
+
-
*Lupus erythematous is an autoimmine disease
+
-
*There are three types of lupus: systemic (SLE), discoid (DLE), and subacute cutaneous (SCLE)
+
-
**Systemic and subacute cutaneous can be '''induced by drugs'''
+
-
*'''All three types of SLE are considered ''idiopathic'''''.
+
-
**A genetic predisposition has been demonstrated.
+
-
*SLE (systemic lupus erythematous) requires 4 of 11 ARA criteria be met.
+
-
*DLE (discoid lupus erythematous) is '''primarily cutaneous''' in manifestation.
+
-
*SCLE (subacute cutaneous lupus erythematous); subacute means it is not quite acute or chronic.
+
-
*Pathogenesis of lupus eyrthmatous is though to be '''UV radiation induced'' and involves formation of '''immune complexes'''.
+
-
 
+
-
=====Systemic lupus erythematous=====
+
-
*Systemic lupus erythematous has 11 diagnostic criteria that can be divided into '''skin and mucus''', '''systemic''', and '''laboratory''' findings.
+
-
**To diagnose SLE, you must "'''DUMP the SAC on the RAC'''"
+
-
*Skin and mucosal criteria (DUMP):
+
-
**Discoid lupus
+
-
**Ulcers (oropharyngela, usually painless)
+
-
**Malar rash
+
-
**Photosensitivity
+
-
*Systemic criteria (SAC):
+
-
**Serositis (pleural, pericardial): inflammation of the serous tissues--things that line the lungs / heart (pleura, pericardium)
+
-
**Arthritis
+
-
**CNS (seizures, psychosis)
+
-
*Laboratory criteria (RAC)
+
-
**Renal dysfunction (Urinary analysis, elevated 24-hour urine protein levels)
+
-
**Antinuclear antibodies (or others like anti-dsDNA or anti-Smith)
+
-
**CBC (Hematology)
+
-
*'''DUMP the SAC on the RAC''' (skin / mucosa, systemic, lab)
+
-
 
+
-
 
+
-
*Systemic lupus erythematous presents with a '''malar rash''' and '''photosensitivity'''
+
-
**There is sometimes "spillover" to unexposed sites, too, with the photosensitivity.
+
-
*SLE can manifest '''[http://editthis.info/iusmicm/Dermatology_-_Hair_Disorders#Scarring_alopecia scarring alopecia]'''
+
-
 
+
-
 
+
-
====Dermatomyositis====
+
-
*Dermatomyositis is an inflammation of the skin and muscle.
+
-
**Note that polymyositis is simply the inflammation of the muscle ''with no skin features''.
+
-
*Like lupus erythematous, '''most dermatomyositis cases are idiopathic'''.
+
-
**'''A small subset of dermatomyositis are drug-induced'''.
+
-
*There is a definite role of '''UV radition in inducing dermatomyositis'''
+
-
*Dermatomyositis is characterized by '''involvement of the complement systems membrane attack complex (MAC)'''
+
-
 
+
-
 
+
-
*Diagnostic criteria for dermatomyositis:
+
-
**Not all 5 are required
+
-
**Skin features (to differentiate it from polymyositis)
+
-
**'''Proximal muscle weakness''' which is usually painless
+
-
**''Muscle enzyme abnormalities'' (identified with CPK and aldolase levels)
+
-
***CPK: creatine phosphokinase; adds kinase to creatinin; MM isoform in skeletal muscle, MB isoform in cardiac muscle, BB in smooth muscle
+
-
**'''EMG abnormalities'''
+
-
**Muscle biopsy
+
-
**(currently we use MRI to dx, too)
+
-
 
+
-
 
+
-
*Dermatomyositis presentation:
+
-
**Heliotrope rash (upper eyelids)
+
-
**Photosensitivity with spillover
+
-
**Poikiloderma: see next section
+
-
**Gottron's papules (area between knuckles is spared)
+
-
**Periungual telangiectasias
+
-
 
+
-
 
+
-
*Heliotrope rash (upper eyelids):
+
-
**http://www.healthsci.jmu.edu/common/Knitter/Graphics/dermatology/heliotrope%20rash.jpg
+
-
**http://www.healthsci.jmu.edu/common/Knitter/Graphics/dermatology/heliotrope%20rash%20II.jpg
+
-
**http://1.bp.blogspot.com/_xzqs4DHM8as/TGroqfIXVSI/AAAAAAAAACg/LvH4C2NjkRs/s320/Heliotrope.jpg
+
-
*Photosensitivity with spillover:
+
-
**http://www.dermaamin.com/site/images/clinical-pic/p/photosensitivity/photosensitivity17.jpg
+
-
**http://www.healthline.com/images/gale/big/gem_04_img0508.jpg
+
-
**http://www.siamhealth.net/public_html/Health/picture/photosensitivity.jpg
+
-
*Poikiloderma: see next section
+
-
*Gottron's papules (area between knuckles is spared):
+
-
**http://imaging.ubmmedica.com/consultantlive/images/articles/2003/07012003/0307ConPERheum2B.jpg
+
-
**http://www.aocd.org/images_ddd/Dermatomyositis_Gottrons_papules_1_low.jpg
+
-
**http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/1866.jpg
+
-
**http://www.curejm.com/symptoms/symptom_gottron1.jpg
+
-
**http://img.medscape.com/pi/features/slideshow-slide/cmsd/fig13.jpg
+
-
*Periungual telangiectasias:
+
-
**http://upload.wikimedia.org/wikipedia/commons/8/82/Dermatomyositis6.jpg
+
-
**http://images.rheumatology.org/image_dir/album75693/md_99-06-0061.tif.jpg
+
-
**http://dermatology.cdlib.org/1502/reviews/photoessay/56.jpg
+
-
 
+
-
=====Poikiloderma=====
+
-
*Poikiloderma is characterized by '''hyperpigmentation, hypopigmentation, telangiectasias, and / or atrophy'''.
+
-
*Poikiloderma is seen in conjunction with '''dermatomyositis, UV radiation damage, and ionizing radiation damage'''.
+
-
*http://www.skinsight.com/images/dx/webAdult/poikilodermaofCivatte_11790_lg.jpg
+
-
*http://www.skincareguide.ca/images/glossary/poikiloderma.jpg
+
-
*http://www.aocd.org/images_ddd/Poikiloderma_1_low.jpg
+
-
*http://www.laserskinsurgery.com/img/Poikiloderma-After.jpg
+
-
*http://www.dermatopedia.com/wp-content/themes/dermatopedia/dermimages/2266_poikiloderma_of_civatte.jpg
+
-
*http://somalaser.com/blog/wp-content/uploads/2011/01/vbmBA2lrg.jpg
+
-
*http://www.doctorv.ca/images/services/light-treatments/ipl_fotofacial_skin_rejuvenation/large_poikiloderma_sun_damage.jpg
+
-
*http://www.danderm-pdv.is.kkh.dk/atlas/pics/3/3-49-4.jpg
+
-
*http://www.riversideonline.com/source/images/slideshow/sn22_poikiloderma.jpg
+
-
*http://www.slievemore1.com/images/cosmetic%20images/ipl7.jpg
+
-
 
+
-
 
+
-
====Drug reactions====
+
-
*Drug reactions '''can generate every possible different cutaneous pattern'''
+
-
*Rarely does clinical presentation afford enough information to dx drug-induced reaction
+
-
**Usually requires additional information like lab values
+
-
*'''Some patterns caused by drug reactions are considered higher risk'''
+
-
**These patterns have significant morbidity or have mortality associated with them
+
-
**'''High risk patterns include''': urticaria / anaphylaxis, erythema multiforme major (SJS, TEN), morbilliform reactions (with hypersensitive syndrome characteristics), and '''vasculitis'''
+
-
*All the rest of the patterns are relatively low risk for morbidity and mortality.
+
-
 
+
-
 
+
-
=====An algorithm for diagnosing drug-induced cutaneous reactions=====
+
-
*The process is, in general, a series of controlled challenges to the pt with the drug: challenge, dechallenge, rechallenge, exlusion
+
-
*First we challenge with the drug
+
-
**An important aspect to the challenge is the time of drug administration
+
-
**This should be informed by the literature and one's own experience with the drug
+
-
*Then we "dechallenge"
+
-
**We watch for cessation of the drug reaction
+
-
**Dechallenging is options, unless the drug is essential for the pt's life
+
-
**Dechallenging will not result in cessation of recation if the reaction is irreversible
+
-
*Next we rechallenge
+
-
**This repetition gives the highest level of certainty that the reaction is drug-induced
+
-
**Rechallenging is optional
+
-
***Rechallenge is not an option if the challenge resulted in a higher-risk reaction pattern (which would advise no rechallenge for safety reasons)
+
-
***Rechallenge is not an options if there is an alternative therapy to the drug that causes a reaction (because we shouldn't give a drug we know causes an adverse reaction is there is still another potentially non-reactive drug available)
+
-
*Finally we exclude
+
-
**If the dechallenge does not generate cessation or if the rechallenge does not cause the same reaction the we exclude drug-induced reactions from the ddx.
+
-
*
+
-
Defining the spectrum •
+
-
Polymyositis (no skin features)
+
-
 
+
-
•
+
-
Dermatomyositis (skin + muscle) both adult and juvenile  Etiology
+
-
 
+
-
•
+
-
Most are idiopathic … genetic susceptibility
+
-
 
+
-
•
+
-
A very small subset are drug-induced  Pathogenesis
+
-
 
+
-
•
+
-
Definite role of UV radiation in disease induction
+
-
 
+
-
•
+
-
Complement membrane attack complex (MAC) has role
+
-
 
+
-
 
+
-
 
+
-
 
+
-
Dermatomyositis Diagnostic Criteria
+
-
Bohan & Peters criteria for diagnosis of dermatomyositis •
+
-
Characteristic skin features
+
-
 
+
-
•
+
-
Proximal muscle weakness  (usually painless)
+
-
 
+
-
•
+
-
Muscle enzyme abnormalties  (CPK, aldolase)
+
-
 
+
-
•
+
-
Characteristic EMG abnormalities
+
-
 
+
-
•
+
-
Muscle biopsy    … currently MRI commonly used to dx muscle disease  **Each of these steps has some degree of limitation; in
+
-
 
+
-
addition, do not need all 5 dx criteria to make diagnosis 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
Dermatomyositis – Clinical Features Heliotrope rash on upper eyelids
+
-
12
+
-
 
+
-
Dermatomyositis – Clinical Features Photosensitivity, tendency towards poikiloderma, “spillover”
+
-
13
+
-
 
+
-
What is “Poikiloderma” ?
+
-
Hyperpigmentation Hypopigmentation Telangiectasias Atrophy  Most commonly seen with … Dermatomyositis UV radiation damage
+
-
 
+
-
Ionizing radiation damage
+
-
 
+
-
Dermatomyositis – Clinical Features Gottron’s papules, periungual telangiectasias
+
-
14
+
-
 
+
-
Dermatomyositis – Clinical Features Gottron’s papules over IP joints, sparing between “knuckles”
+
-
15
+
-
 
+
-
Diagnosis of Cutaneous Drug Reactions Background Information
+
-
Key realities •
+
-
Virtually any inflammatory cutaneous reaction pattern can be drug-induced at times
+
-
 
+
-
•
+
-
Seldom does the clinical appearance alone point to a drug etiology (without aid of additional clinical information)  Higher risk
+
-
 
+
-
drug reaction patterns can either cause …
+
-
 
+
-
•
+
-
Fatal outcome (even if only remotely possible)
+
-
 
+
-
•
+
-
Significant, irreversible morbidity 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
Diagnosis of Cutaneous Drug Reactions Higher Risk Drug Reaction Patterns
+
-
Urticaria / Anaphylaxis  Erythema multiforme major  Stevens-Johnson syndrome  Toxic epidermal necrolysis  Morbilliform reactions
+
-
 
+
-
with “hypersensitivity syndrome”  Vasculitis  … and the rest are relatively low risk (vast majority of rxn)
+
-
 
+
-
Diagnosis of Cutaneous Drug Reactions An Algorithm
+
-
Challenge •
+
-
Timing of drug administration
+
-
 
+
-
•
+
-
Literature reputation
+
-
 
+
-
•
+
-
Personal experience  (… the least important component) Dechallenge
+
-
 
+
-
•
+
-
Response to drug cessation
+
-
 
+
-
•
+
-
Optional – not if essential drug; no help if rxn irreversible Rechallenge
+
-
 
+
-
•
+
-
Gives highest level of certainty of algorithm steps
+
-
 
+
-
•
+
-
Optional – not if higher risk pattern, not if alternative Rx Exclusion  (of non-drug causes of same pattern) 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
 
+
-
  It does not get any better than this …
+
-
 
+
-
 
+
-
  Thank you for  your interest !!
+

Current revision as of 08:16, 28 February 2013

R5Wral Say, you got a nice article.Much thanks again.

Retrieved from "http://editthis.info/iusmicm/Dermatology_-_Bright_Red_Rashes"
Personal tools