Tackle rashes with wisdom from Kashlak’s resident Skinternist (or Internist-Externist) Dr. Helena Pasieka (MedStar, Georgetown), board certified in both Internal Medicine and Dermatology. She offers “a rash approach to rashes” including: initial triage, ‘inside job’ vs ‘outside job’, differential diagnosis, a review of common culprits, basic management techniques, and how to determine if the reaction is life-threatening. Plus, Dr Pasieka teaches us how to handle family and friends asking, “Can you take a look at this rash?”.
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Written and Produced: Beth Garbitelli MS2
Infographic and Cover Art: Beth Garbitelli MS2
Hosts: Stuart Bringham MD, Matthew Watto MD, Paul Williams MD
Editor: Matthew Watto MD
Guest: Helena Pasieka MD
Dermatology is medicine. Remember what you learned in intern year: how to differentiate sick versus not sick. This is the first threshold for addressing rash.
“Inside job”: Does the rash have an internal cause (e.g. histamine degranulation, or systemic illness)? These rashes from an ‘inside job’ like hives are diffuse, symmetric, and bilateral.
“Outside job”: Rashes with an external cause tend to be unilateral and asymmetric e.g. contact dermatitis, cellulitis, or other types of infection.
Familiarize yourself with what different types of eruptions look like on ALL pigments of skin.
Suspected severe drug reaction with rash: Perform a thorough physical exam with a focus on mucosal regions (oral, nasal, ocular, vulvar/vaginal in women, urethral, perianal).
Describe what you see in regular, old words. Don’t try to “speak derm” if you don’t speak derm. You’ll cause more confusion.
Urticarial (hives) or morbilliform? 1) Use a skin marker to draw around the rash. Then, examine the next day. Hives may change location, but morbilliform lesions do not move. 2) Use the wooden end of a cotton tipped applicator to check for dermatographism (suggestive of urticaria) –Dr Pasieka’s expert recommendation
Morbilliform Rashes: An itchy, symmetric, bilateral, diffuse, truncal rash is likely to be a benign morbilliform drug eruption. These are common and you can “treat through” if organs are spared and the reaction is limited to skin.
Timing differentiates types of severe drug reaction: It can be tedious to figure out when people started and stopped medications. But, the timeline is critical in determining between AGEP (<3 days), SJS/TEN (4-10 days), and DRESS/DIHS (often 6 weeks).
Patients with SJS or TEN will feel very sick, have mucosal site involvement, skin pain, and a positive Nikolsky sign. When patients fit these criteria, admit them to the ICU, call dermatology immediately, stop every drug that is unnecessary, and carefully initiate a fluids.
Complications of SJS/TEN: Over 50% of patients surviving TEN suffer from long-term sequelae of the disease, including ocular and gynecological issues. Consult with ophthalmology and gynecology early if managing patients who have experienced SJS/TEN.
How to handle family and friends asking about rashes: Tell them you need to see ALL the skin. Lighting is not great at parties. Maybe there’s too many cocktails on board. And, anything less than a full skin exam is doing them a disservice (Dr. Pasieka’s expert recommendation).
Dermatology is medicine. Remember what you learned in intern year: how to differentiate sick versus not sick. When a patient presents with a rash, perform an assessment of the patient’s current state and how sick they appear. This is the initial threshold for serious cutaneous reactions to drugs and other life-threatening emergencies in dermatology. Go back to fundamentals. Namely, a thorough review of systems and physical exam are essential for proper assessment of potential drug rash.
Certain drugs are more commonly associated with the life-threatening drug reactions and rashes, Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). They include antibiotics (trimethoprim-sulfamethoxazole and other sulfonamide antibiotics, as well as aminopenicillins, quinolones, and cephalosporins), allopurinol, aromatic anticonvulsants, certain antiretroviral medications, NSAIDs and more (Dodiuk-Gad, 2015 ; Lin 2004).
A complete review of systems is very important (Santistevan 2017). Symptoms to ask about specifically include fever, feelings of malaise, flu-like feelings, pharyngitis, and upset stomach. While diarrhea and vomiting are uncommon with drug eruptions, unsettled stomach, and pharyngitis can indicate involvement of the alimentary canal (Schwartz 2013). Additionally, determine a timeline for symptom progression. Assess how the skin feels to patient. Is it painful or not painful? Skin that feels itchy to the point of burning/tingling, or painful like a sunburn is concerning. Per Dr. Pasieka, rashes that itch are usually benign.
Familiarize yourself with what different types of eruptions look like on ALL pigments of skin. Drug reactions may have more severe complications in those with more deeply pigmented skin (Thorel 2019).
Perform a thorough physical exam with a focus on mucosal regions (oral, nasal, ocular, vulvar/vaginal in women, urethral, perianal) (Schwartz 2013). Signs of conjunctivitis or irritated eyes may also indicate severe drug reaction (Harr 2010) . The GU systems may also be implicated so symptoms of urethritis, painful defecation, or blood in stool must be ascertained in somebody with this history (Schwartz 2013).
The genitourinary components of this exam are often missed but are a critical aspect. A full body skin exam is extremely important in a potential drug rash since in over 90% of SJS/TEN cases have mucosal site involvement (Harr 2010) . This can be a litmus test for your threshold of suspicion.
Kashlak Pearl: Dr. Pasieka finds it helpful to think about rashes based on cause, an internal cause such as histamine degranulation (‘inside job’) versus external causes such as contact dermatitis (‘outside job’). Rashes from an ‘inside job’ like hives or urticaria are diffuse, symmetric, and bilateral. In an ‘outside job’ like contact dermatitis, cellulitis, other types of infection, rashes are unilateral and asymmetric.
Location can indicate certain types of causes as well. Drug reactions tend to evolve centrally, moving from trunk to extremities. Eczema, contact dermatitis, allergic manifestations, and tinea tend to manifest distally per Dr. Pasieka.
Describe what you see in regular, old words. You’re there to be an advocate for your patients. Trying to use a speciality-specific vernacular that you don’t speak well can cause more confusion. Don’t say erythematous, just describe the color (ie: red, lilac, purple, brown), per Dr. Pasieka.
Example: “Gentleman is here and looks unwell, his mucosal sites are inflamed. He’s complaining of a sore throat. He has dry eye, and when I look at his skin, it is inflamed, pink and purple, moist, and in some areas, it is eroded. Patient has skin pain, not skin itching.”
Kashlak Pearl: Dr. Pasieka points out, a patient with an itchy, truncal rash with pristine mucosa (ie: without dry eye, ocular pain, conjunctivitis, urethritis, perirectal pain) in the absence of blisters and erosions on skin, is unlikely to be experiencing a life-threatening reaction.
An itchy, symmetric, bilateral, diffuse, truncal rash in the absence of other signs mentioned above, is likely a benign morbilliform drug eruption. These are common, pesky, and uncomfortable. Exanthematous drug eruptions, also called morbilliform or maculopapular drug rashes, occur in 1 to 5% of first-time users of many types of drugs (Stern 2012).
In absence of concerning drug reaction symptoms (pain, mucosal involvement, pancytopenia, LFT abnormalities, renal dysfunction), you may treat through it with palliative treatment only if the causative drug is a clinical need (ie: in hypersensitivity in HIV-positive patients, patients with cystic fibrosis, etc.) (Scherer 2013).
Urticaria and morbilliform rashes have a different treatment algorithm. Urticaria changes or disappears rapidly while morbilliform rashes will persist for 48-72 hours regardless of therapy.
Kashlak Pearl: Dr. Pasieka advises using a skin marker (‘give the patient a temporary tattoo’) to draw around the rash. Then, examine the next day. An urticarial rash may change locations, but morbilliform lesions will not move around.
Kashlak Pearl: Another ‘tip’ is to assess for dermatographism using a cotton tip applicator’s wooden end. Draw something with the applicator (tic-tac-toe, ‘Go Yankees’, etc.) Check it after five minutes. All skin types will become irritated, but look and feel for raised/welted skin, indicating urticaria (Schaefer 2017).
Kashlak Pearl: Dr Pasieka notes, antihistamines will stop new hives from forming in the next 6-12 hrs, but do not treat the hives already present.
The phenomenon of itch is very complex and involves more than just histamines (Yosipovitch 2013). In a morbilliform rash, antihistamines may assist with itch relief but will not completely relieve symptoms (Stern 2012). Dr. Pasieka recommends, if a rash is not dermatographic, doesn’t look juicy or dermal, then treat with topical steroid ointments (like triamcinolone) twice a day and withdraw the potential causative agent (Stern 2012). “Make them greasy”. It will take up to 72 hours before a morbilliform drug rash will regress, even with treatment.
Use timing to assist in differentiating between the main types of severe drug reaction. It can be tedious to figure out when people started and stopped medications, but the timeline is critical in determining if a patient has Acute generalized exanthematous pustulosis (AGEP), Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), or Drug reaction with eosinophilia and systemic symptoms (DRESS), also termed drug-induced hypersensitivity syndrome (DIHS).
AGEP begins 1-3 days after drug therapy. It is rarely life-threatening, but can be severe in up to 20% of cases leading to systemic involvement (Feldmeyer 2016). Mortality from AGEP comes from insensible losses, loss of heat, and electrolyte imbalances; especially in patients with predisposing issues such as renal dysfunction or cardiac disease (Hotz 2013). Dr Pasieka notes, a classic presentation is a patient treated with an IV 3rd generation cephalosporins for hospital-acquired pneumonia. Other typical causative agents include several types of antimicrobials, antimalarials, and calcium channel blockers (Chu UpToDate 2019).
The rash of AGEP is studded with innumerable, pinpoint pustules (Feldmeyer 2016). Additionally, it will be brightly erythematous, often in areas where skin touches skin (ie: flexural areas, intertriginous regions) (Szatkowski 2015). Dr. Pasieka points out, when those little pustules are clustered together, there may be superficial desquamation and a denuded-ness to the upper layer of skin. AGEP involves a paper thin, very wet, stratum corneum, whereas SJS/TEN rashes implicate the thick dermis below it.
SJS & TEN are the same disease on a continuum of severity. They occur from drugs started between 4 and 14 days before rash onset. SJS involves less than 10% of body surface area (BSA), SJS/TEN overlap is 10-30%, and TEN involves greater than 30% BSA. SJS and TEN also feature total epidermal detachment, indicated by a positive Nikolsky sign (Schwartz 2013). Dr Pasieka describes how to check for the Nikolsky sign: take a finger against normal appearing skin and push down (apply lateral pressure), or pull the edge of an existing blister. A positive Nikolsky sign is the top layers sloughing off of the lower layers from this motion.
Patients with SJS or TEN will feel very sick, have mucosal site involvement, skin pain, and a positive Nikolsky (Schwartz 2013). When seeing a patient that fits these criteria, admit them to the ICU, call dermatology immediately, stop every drug that is unnecessary, and carefully initiate a fluid regimen (Dr. Pasieka’s Expert Recommendation).
Over 50% of patients surviving TEN suffer from long-term sequelae of the disease (Harr 2010).
Survivors of SJS/TEN can have severe ocular surface disease (Kohanim 2016). Patients may experience chronic dry eye, corneal opacification, corneal ulceration, and symblepharon (partial or complete adhesion of the palpebral conjunctiva of the eyelid to the bulbar conjunctiva of the eyeball). Bring ophthalmology on board sooner rather than later!
Up to 70% of women with SJS/TEN will have acute manifestations of vulvar or vulvarvaginal lesions (Meneux 1997). Women surviving SJS/TEN have increased risk for urethral stenosis, vaginal stenosis, and vaginal adhesions/agglutination/adenosis (Niemeijer 2009). Patients may also experience dyspareunia, pain and irritation (Olteanu 2018). Consult with gynecology early to ensure these issues are addressed with SJS/TEN survivors.
DRESS/DIHS has no “classic” rash. But, it often presents with facial edema denoted by effacement of the nasolabial folds (Eshki 2009). DRESS/DIHS rash is heterogeneous and varies greatly from patient to patient (may resemble erythema multiforme, eczema , lichenoid, morbilliform, etc).
Kashlak Pearl: Dr. Pasieka assesses for facial edema by comparing the patient’s face to their driver’s license or student ID.
There are two recently developed diagnostic criteria, European Registry of Severe Cutaneous Adverse Reaction and Japanese Research Committee on Severe Cutaneous Adverse Reaction scoring system. These are mainly for research purposes, but may inform the probability of DRESS/DIHS (Husain 2013).
Kashlak Pearl: Dr. Pasieka asks patients to recall drug initiation based on seasons or holidays since this reaction occurs many weeks later.
DRESS/DIHS patients feel sick with systemic symptoms like fever, malaise, and GI upset. In addition to rash, at least 70% of DRESS/DIHS patients display liver abnormalities (Husain 2013). Cardio-pulmonary systems are not often involved. But, when present can be a cause for mortality due to severe refractory pneumonitis, cardiac myositis, acute heart failure, or arrhythmias (Husain 2013). Dr. Pasieka notes, there’s often lag in the onset of hypothyroidism (after acute thyroiditis) by about 6-8 weeks. Stay vigilant!
To treat, stop the offending medication and initiate a steroid course. Due to rebound potential, the systemic steroids must be administered with a slow prolonged taper (Husain 2013). Dr. Pasieka explains that in some cases topical steroids may be used and the patient closely monitored, if organs are spared and the reaction is limited to skin.
Listeners will learn how to screen, assess, and categorize potential drug rashes seen in clinic as well as differentiate between severe adverse drug rashes.
After listening to this episode listeners will…
*The Curbsiders participates in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising commissions by linking to Amazon. Simply put, if you click on my Amazon.com links and buy something we earn a (very) small commission, yet you don’t pay any extra.
Dr. Pasieka reports no relevant financial disclosures. The Curbsiders report no relevant financial disclosures.
Pasieka, Helena. Guest expert. “#161 A Rash Approach to Rashes”. The Curbsiders Internal Medicine Podcast. http://thecurbsiders.com/ July 15, 2019.
The Curbsiders are partnering with VCU Health Continuing Education to offer FREE continuing education credits for physicians and other healthcare professionals. Visit curbsiders.vcuhealth.org and search for this episode to claim credit.
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Comments
Link to the NEJM article cited by Helena?
Hi May, Here is the link: " The phenomenon of itch is very complex and involves more than just histamines (Yosipovitch 2013)." https://www.nejm.org/doi/full/10.1056/NEJMcp1208814...You can find this in the show notes as well.
Fantastic podcast. Very practical. Thanks! Couple questions: If someone appears on hx and px to have a benign drug eruption, should you always get a CBC, LFTs and renal function tests or if you have reliable follow up is the reassuring hx and px sufficient? If they had that benign drug eruption once, will they have it in future with that medication? My understanding is that they might but it won't be worse with future exposures (like anaphylaxis)- is that right? So it's a medication to avoid, but can be used in the future if needed. Is that fair? Also, do you do HLA testing before prescribing certain medications (eg allopurinol)? Should we have a list of medications that we always do HLA testing in (at least in certain populations) before prescribing?
Hi Judith, Pharmacist here - definitely can't comment on the first portion of your question, but I can discuss in detail the HLA portion of your question. The short answer is in certain populations, HLA testing is recommended prior to initiation of certain medications. The two resources I can point you to are the CPIC guidelines (Clinical Pharmacogenetics Implementation Consortium) as well as pharmgkb.org which has a lot of interactive tools to help put the CPIC guidelines into practice. For Allopurinol specifically, the Han-Chinese population is recommended to be screened for the presence of HLA-B*58:01. For Carbamazepine the Han-Chinese, Vietnamese, Cambodian, Thai, Indian, Malaysian, and Hong Kong descendants are recommended to be treated for presence of HLA-B*15:02. For Abacavir, everyone should be screened for HLA-B*5701. Alternatively, there is no screening recommendations for HLA-B*38 prior to sulfamethoxaxole use (although it's most common in those of European ancestry). Of note, CPIC and PharmGKB are beneficial for also pharmacogenomic considerations of drug use (CYP isoenzymes, VKORC1 mutations, etc). Hope that helps! Brian
Thank you!
Hello, How can I obtain CME for this talk ? thanks
Hi May, all of the shows that qualify for MOC/CME credits are found here: https://www.acponline.org/cme-moc/cme/internal-medicine-podcasts/the-curbsiders-podcast
Helena here, from Kashlack Memorial. I agree with Brian S’s reply above regarding HLA testing for certain agents and in certain populations (such as in Han Chinese). Rechallenge in morbilliform drug eruption, in my experience tends to be a more abrupt in onset, and more extensive upon re-exposure. Thanks to The Curbsiders for such a great infographic, and such fun in recording.