DERMATOLOGY FOR THE INTERNIST:DIFFERENTIATING EMERGENCIES FROM ROUTINE RASHES

Dr. Kelli Lovelace MD

Tulsa Dermatology Clinic

OVERVIEW

• Drug Rashes• Morbilliform

• Severe Cutaneous Adverse Reactions (SCAR)

• Erythroderma

• Dangerous presentations of common skin disorders

• Pustular psoriasis

• Eczema Herpeticum

• Differentiating dangerous from common skin disorders

• LCV and HSP

• Stasis dermatitis

DRUG REACTIONS

• In most of the cases, drug hypersensitivity presents as generalized maculopapular (morbilliform) type rash, which is mild and self-limited after withdrawing the causative agents.

• However, in a small fraction of the cases, drug hypersensitivity would show up as a severe drug reaction.

• These severe reactions are life-threatening and termed as severe cutaneous adverse reactions (SCARs).

MORBILLIFORM DRUG RASH

• Looks like measles

• Itches instead of hurts

• 95% of drug reactions

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MORBILLIFORM DRUG RASH

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SEVERE CUTANEOUS ADVERSE REACTIONS (SCAR)

• Stevens Johnsons Syndrome (SJS)

• Toxic Epidermal Necrolysis (TEN)

• Drug Rash with Eosinophilia and Systemic Symptoms (DRESS)

• Acute Generalized Eruptive Pustulosis (AGEP)

STEVENS JOHNSONS SYNDROME /TOXIC EPIDERMAL NECROLYSIS

SPECTRUM• Overlap in this spectrum of diseases

• Delineating one from another using percent of body surface area involved (BSA) and areas of skin involved (mucosa vs cutaneous skin)

• Stevens-Johnson Syndrome (<10% BSA)

• Mucosal involvement

• SJS/TEN Overlap 10-30% BSA

• Toxic Epidermal Necrolysis (>30% BSA)

• Diffuse sloughing of the skin

• Can be fatal

ETIOLOGY

• A combination of drug structure and host genetic factors (such as drug metabolism, immunity, and T cell clonotypes) contribute to the etiology of SJS/TEN.

• SJS/TEN, from an immunologic standpoint, appears to behave most like a delayed-type hypersensitivity reaction (DTH)

JAMA Dermatol. 2017;153(12):1344. doi:10.1001/jamadermatol.2017.3957

SJS/TEN

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TEN

PRESENTATION OF SJS/TEN

• Presentation 1-3 weeks after drug initiation

• Systemic symptoms may precede skin and mucous membrane findings by 1 to 3 days. Symptoms may include pain of the skin, eyes, or other mucous membranes, headaches, rhinitis, malaise, sore throat, cough, and myalgias

• The hallmark feature of SJS/TEN is mucosal involvement (present in 80% of cases)

• Skin lesions are erythematous, irregularly shaped, dusky red to purpuric macules (atypical targets) which progressively coalesce

• Can rapidly spread to rest of the body

• Nikolsky sign: slipping away of the upper layers of the skin from the lower layers when the skin is slightly rubbed.

• PAIN is more prominent then itch compared to morbilliform eruptions

MEDICATIONS THAT CAUSE SJS/TEN

SATAN

• Sulfonamides: cotrimoxazole, sulfasalazine

• Allopurinol, especially in doses of more than 100 mg per day

• Tetracycline (Antibiotics): penicillins, cephalosporins, quinolones, minocycline

• Anticonvulsants: lamotrigine, carbamazepine, phenytoin, phenobarbitone

• Nonsteroidal anti-inflammatory drugs (NSAIDs) (oxicam type mainly)

• Nevirapine (non-nucleoside reverse-transcriptase inhibitor)

SCORTEN

• SCORTEN is a measure of severity of illness for toxic epidermal necrolysis.

• A score is determined by the number of risk factors that are present.

• The higher the score is, the greater the mortality rate for the patient

• The absence of a risk factor is scored as zero; the presence of a risk factor is scored as one.

• SCORTEN ranges from zero to seven

SCORTENSCORTEN scaleRisk factors present Mortality rate (%)

0–1 3

2 12

3 35

4 58

≥5 90

The presence or absence of seven risk factors is used to

determine the SCORTEN:

(1) age >40 years

(2) malignancy

(3) total body surface area affected >10 percent

(4) heart rate >120 beats per minute

(5) blood urea nitrogen >28 mg per dl

(6) serum glucose >250 mg per dl

(7) serum bicarbonate <20 mEq per l

MANAGEMENT

• Recognize the presentation

• Stop offending drug

• Provide supportive care

• Dermatology Consult if available

• Transfer to a burn unit or referral center

DRUG REACTION WITH EOSINOPHILIA AND SYSTEMIC SYMPTOMS (DRESS)

• Start of disease after drug exposure is long, usually between 3-8 weeks

• Life threatening drug induced hypersensitivity syndrome with fever, cutaneous eruptions, and internal organ involvement

• Internal organ involvement, liver most common (75-90%) followed by kidney, lung and heart

• Desquamation of skin with resolution

• Mortality rate is around 10%

DRESS

• Facial edema (76% of patients)

• Erythematous macular rash with infiltrated papules and markedly purpuric change over 50% BSA

• Mucosal lesions in more then 50% of patients, mouth and lips most common sites

• Lymphadenopathy

• Hepatosplenomegaly

• Eosinophilia

• Atypical lymphocytosis

• Abnormal LFT’s

DRESS

Arch Dermatol. 2010;146(12):1373-1379. doi:10.1001/archdermatol.2010.198

MEDICATIONS THAT CAUSE DRESS

• Allopurinol

• Antibiotics

• Sulfonomides

• Vancomycin

• Minocycline

• Amoxicillin

• Anti-TB drugs

• Anticonvulsants (lamotrigine, phenytoin, carbamazepine)

• NSAIDS

• Anti-HIV drugs

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DRESS SEQUELA

• Treatment with long steroid taper (months)

• Association with autoimmune diseases

• Monitor for long term changes in thyroid function, pancreatic involvement including pancreatitis and diabetes mellitus type 1.

ACUTE GENERALIZED EXANTHEMATOUS PUSTULOSIS

• Usually presents in 1-2 days

• Sudden on set of at least dozens and often hundreds of sterile nonfollicularpustules (sheets of pustules)

• Fever, neutrophilia

• Mucosal lesions are rare, palms and soles usually not involved

• Sometimes facial edema, blisters or atypical target lesions

• Systemic involvement in less then 20%

• Liver most common followed by kidney, lung and bone marrow

AGEP• Rarely viral

• Most commonly drug• Antibiotics

• Amoxicillin• Macrolides• Tetracyclines• Quinolones• Sulfonamides

• Hydroxycholorquine• Terbinafine• Diltiazem• NSAIDS

• If antibiotic is cause commonly presents in one to two days

• If other medication mean duration is 11 days

AGEP

AGEP

COMPARISON OF SCAR FINDINGS

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ERYTHRODERMA

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5 CAUSES OF ERYTHRODERMA

• Psoriasis

• Eczema

• Medication reaction

• Pityriasis Rubra Pilaris

• Mycosis fungoides (Sezary syndrome)

PRP

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MYCOSIS FUNGOIDES

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ERYTHRODERMA

• Patient is unwell with fever, temperature dysregulation and loss of fluid through the skin.

• Heat loss leads to hypothermia.

• Fluid loss leads to electrolyte abnormalities and dehydration.

• High-output heart failure (thought to be due to red skin/vasodialation)

• Hypoalbuminemia from protein loss and increased metabolic rate causes edema.

MANAGEMENT

• Identify the cause• History

• Previous skin condition• Medications

• Physical exam• Nails• Lymphadenopathy• Scale• Islands of sparing

• Biopsy• Skin• Lymph nodes if indicated

• Supportive care

• Steroids topically

• Systemic treatment according to underlying disease

PSORIASIS VS PUSTULAR PSORIASIS

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PUSTULAR PSORIASIS

• Types• Generalized• Annular• Exanthematous• Localized

• Generalized pustular psoriasis (GPP), or psoriasis of von Zumbusch, is an acute and potentially grave clinical form, which occurs usually in patients with psoriasis who undergo aggravating factors, but which may arise in patients without previous history of psoriasis.

• Causes• Infections• Sunburns• Medications (lithium, salicylates, tar, chloroquine and beta-blockers)• Systemic corticosteroids

ECZEMA VS ECZEMA HERPETICUM

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ECZEMA HERPETICUM

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ECZEMA HERPETICUM

• Eczema herpeticum can be severe, progressing to disseminated infection and death if untreated.

• Bacterial superinfection and bacteremia are usually the complications that cause mortality.

• In an immunocompromised patient, the mortality rate is reported to be as high as 6% to 10%

• Oral antiviral treatment in healthy outpatients, IV antiviral in immunocompromised or infants

• Preventative oral antivirals in patients at high risk (wrestlers, patients with a history of eczema herpeticum)

SCHAMBURGS PURPURA VS LEUKOCYTOCLASTIC VASCULITIS

(LCV)/HENOCH- SCHONLEIN PURPURA(HSP)

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LEUKOCYTOCLASTIC VASCULITIS (LCV)AND HENOCH SCHOENLEIN

PURPURA (HSP)• Palpable purpura, some lesions have central pustules

• Small vessel neutrophilic vasculitis

• Blood work to look for renal involvement along with UA to look for blood or protein, some experts recommend monthly UA for up to six months

• Immunofluorescence on biopsy to look for IgA in patients with features suggestive of HSP

BILATERAL CELLULITIS VS STASIS DERMATITIS/LIPODERMATOSCLEROSIS

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STASIS DERMATITIS

• Bilateral cellulitis is very rare

• Left leg may be more swollen then right due to venous return to the heart

• No systemic symptoms, normal white count