Skin Drug Rxn

Differentiate btw Non/Immunological drug Rxns:

• Prevalence/Predictability:

• Dif Types

Non- Immunological

• Prevalence/Predictability:

  • More common (80%) , 

  • predictable dose dependent.

• Different Types:

  • Pharmacological AEs

  • Idiosyncratic reactions

  • Intolerance (HIP

  • Jarisch-Hexhemeier reaction (Penicillin)

Immunological

• Prevalence/Predictability:

  • Less common

  • Less predictable (not dose-dependent (latent period).

• Different Types:

  • Types I, II, III, IV

    • Pathogenesis Mech. = Unknown

List the Common Drugs Causing Reactions

Common Drugs Causing Reactions

• Sulfonamides

• NSAID's

• Antimalarial

• Antibiotics

• Allopurinol

• Anti-TB

• Antiepileptics

• Antihypertensives

• Antiretrovirals

High Risk Categories for drug rxns

High Risk Categories

• Polypharmacy/PMH of drug reaction/allergy.

• FH of drug reaction .

• Autoimmune CT diseases

  • SLE, rheumatoid arthritis.

• Immunocompromised or Renal/hepatic impairment 

  • e.g. AIDS, viral infections (HHV, EBV, CMV & HIV)

SLE

Describe SLE

• Common Symptoms:

• Drugs that Evoke SLE: 

  • MEMTIP

Systemic lupus erythematosus (SLE)

• Common Symptoms:

  • Butterfly rash, 

  • Arthralgia 

  • Photosensitivity.

  • Other

    • Numbness, tingling, pleural effusion, pulmonary hypertension

• Drugs that Evoke SLE: MEMTIP: HIP

  • hydralazine, isoniazid, procainamide

    • slow acetylators

Fixed drug eruption (FDE)

Describe Fixed drug eruption (FDE)

• What is it?

• MOA

• Drugs that Causes this:

Fixed drug eruption (FDE)

• What is it?

  • Eruptions @ same site every time drug administered

    • Often: mucocutaneous junctions

• MOA

  • Cytotoxic T lymphocytes Act. in Basal Layer 

• Drugs that Causes this:

  • Antibacterial agents 

    • (trimethoprim-sulfamethoxazole, 

    • tetracyclines, 

    • penicillins, 

    • Quinolones,

    • dapsone

  • NSAIDs; 

    • acetylsalicylic acid, 

    • ibuprofen, 

    • naproxen, 

    • mefenamic acid)

  • Acetaminophen (paracetamol)

  • Barbiturates

  • Antimalarials

List the Adverse drug reactions in skin that can result in death

Adverse drug reactions in skin that can result in death

• TENS (30-35%)

• SJS

• DRESS

TENS

TENS

Describe TEN

• Symptoms:

• Locations:

• Lesion Characteristics:

Toxic epidermal necrolysis (TEN)

• Symptoms:

  • Marked Epidermal/Mucosa(oral) Necrosis/Exfoliation -> Blistering/Erosions 

  • Erythema

  • Fever

  • Fatigue

• Locations:

  • Whole Body; Gradually Spread

• Lesion Characteristics:

  • Target Lesions w/ dusky centers 

List the Drugs that Causes TENS

Drugs that Causes TENS

• Antibacterial drugs 

  • Sulfa- Drugs (sulfonamides): (penicillin)

  • Cephalosporins

• Antiepileptics 

  • (carbamazapine, phenytoin, phenobarbital, lamotrigine, Valproic Acid)

• Allopurinol

• NSAID’s 

  • (Piroxicam).

• Anti-HIV 

  • (Nevirapine).

• Methotrexate

What is the nmeuonic for remembering drugs that can cause TENS/SJS?

PCP LAPSE:

• Phenytoin,

• Carbamazepine,

• Phenobarbital,

• Lamotrigine,

• Allopurinol,

• Penicillin,

• Sulfa drugs,

• Erythromycin

What are the differences in Erythema Multiforme vs SJS vs TENs?

Erythema Multiforme

SJS

TENS

SJS

SJS

DRESS

Describe DIHS/DRESS

• Symptoms:

• Drugs Causing this:

DIHS/DRESS

• Symptoms:

  • Maculopapular rash  (>3 wks)

  • Lymphadenopathy

  • Fever (>38°C)

  • Leukocytosis

  • Atypical lymphocytosis

  • Eosinophilia

  • Hepatitis (ALT >100 U/L)

  • HHV-6 reactivation

---

Drugs Causing this:

• Sulfonamides

• Antibiotics

• NSAIDs

• Antiepileptics

• Allopurinol

• Antihypertensives

• Antimalarials

• Antitubercular drugs

• Antiretrovirals (nevirapine)

Dx criteria for A-DRESS?

Describe Jarisch-herxheinzer Rxn

• What causes this?

• MOA:

• Tx:

• Symptoms:

Jarisch-herxheinzer Rxn

• What causes this?

  • Penicillin in syphilitic patients( secondary syphilis)

• MOA:

  • Bacteria (spirochetes) die -> endotoxins released in Intracell. Matrix -> body can’t remove it fast enough

• Tx:

  • Dose not need interruption of therapy

  • Aspirin & sedation gives relief.

---

Symptoms:

• Shivering/chills

• HA

• Meningism

• Fever, 

• Myalgia, 

• Exacerbation of lesion, 

• Vascular collapse

• Hypotension (vasodilation)

• Mental Fog

• Skin Rash

• Loose Stool

Photosensitivity

Contact Dermatitis

Differentiate between Phototoxic/Photoallergic

• MOa

• Causative Drugs

Phototoxic

• MOA:

  • Drug/Metabolites -> skin accumulation -> absorbs light -> local tissue damage

    • Sunburn Like 

      • (erythema, edema, blistering, hyper pigmentation)

• Causative Drugs:

  • Tetracyclines (esp. Demeclocycline), 

  • Tar products,

  • Nalidixic acid, 

  • Fluoroquinolones, 

  • Sulfones 

---

Photo allergic: 

• MOA:

  • Drug/Metabolites -> Cell-mediated immune response -> absorb light -> papular or eczematous contact dermatitis

• Causative Drugs:

  • Sulfonamides, 

  • Sulfonylureas, 

  • Griseofulvin, 

  • Chloroquine

  • Chlorpromazine

Livedo Reticularis

Describe Livedo Reticularis

• Causative Drug?

• Symptoms

Livedo Reticularis

• Causative Drug?

  • Amantadine 

• Symptoms

  • “Purplish Lavender networking of the thighs”.

  • Irregular pattern of bluish or purplish rash.

  • Numbness or tingling.

Purple Toe Syndrome

Describe Purple toes syndrome

• Causative Drugs

• Symptoms:

• MOA:

• Tx:

Purple toes syndrome

• Causative Drugs

  • Anticoags: Coumadin (warfarin) (3-8 wks after)

• Symptoms:

  • Bilat, painful, purple nonhemorrhagic Lesions

    • Toes/Sides of Feet

      • Blanch w/ pressure

• MOA:

  • Release of atheromatous plaque emboli

• Tx:

  • Discontinue Drug