Generalized Rash

Aka: Generalized Rash, Diffuse Dermatitis

1. See Also
   1. Pruritus
   2. Fever and Rash
   3. Rash in the Febrile Traveler
   4. Skin Infection
   5. Newborn Skin Exam
   6. Dermatologic Manifestations of HIV
   7. Skin Conditions in Diabetes Mellitus
2. Causes: Common
   1. Eczematous Conditions
      1. Atopic Dermatitis
      2. Nummular Exczema
   2. Plaques and patches
      1. Psoriasis or Guttate Psoriasis
      2. Seborrheic Dermatitis
      3. Lichen Planus
      4. Pityriasis Rosea
   3. Local, systemic, or environmental reactions
      1. Contact Dermatitis
      2. Drug Eruption
      3. Erythema Multiforme
      4. Urticaria
      5. Insect Bites
      6. Keratosis Pilaris
      7. Miliaria rubra (Heat rash)
   4. Skin Infections
      1. Tinea Corporis
      2. Scabies
      3. Folliculitis
   5. Viral Exanthems
      1. Roseola (Exanthem Subitum)
      2. Varicella
      3. Fifth Disease (Erythema Infectiosum)
3. Causes: Uncommon (but serious)
   1. Vesicular or Bullous
      1. Bullous Pemphigoid
      2. Dermatitis Herpetiformis
      3. Stephens-Johnson Syndrome (Toxic Epidermal Necrolysis)
      4. ID Reaction
   2. Infectious Causes or Fever and Rash
      1. Lyme Disease
      2. Meningococcemia
      3. Rocky Mountain Spotted Fever
      4. Scarlet Fever
      5. Secondary Syphilis
      6. Staphylococcal Scalded Skin Syndrome
      7. Kawasaki Disease
      8. Acute Retroviral Syndrome withn rash
      9. Toxic Shock Syndrome
   3. Miscellaneous Causes
      1. Cutaneous Lupus
      2. Sweet Syndrome
      3. Cutaneous T-Cell Lymphoma (Mycosis Fungoides)
4. Causes: Rare
   1. Lichen Nitidus
   2. Pityriasis lichenoides
   3. Pityriasis rubra pilaris
   4. Rickettsialpox
   5. Rubella
   6. Rubeola
5. History: Distinctive Findings
   1. Pruritus
      1. Atopic Dermatitis
      2. Nummular eczema
      3. Contact Dermatitis
      4. Insect Bites
      5. Lichen Planus
      6. Scabies
      7. Urticaria
      8. Varicella
   2. Palm and Sole Involvement (See Hand Dermatitis or Foot Dermatitis)
      1. Contact Dermatitis
      2. Erythema Multiforme
      3. Kawasaki Disease
      4. Rocky Mountain Spotted Fever
      5. Rubella
      6. Scabies
      7. Secondary Syphillis
      8. Staphylococcal Scalded Skin Syndrome
      9. Tinea Corporis
      10. Stephens-Johnson Syndrome (Toxic Epidermal Necrolysis)
      11. Toxic Shock Syndrome
6. Labs; Biopsy
   1. General
      1. Prior to biopsy, review stains (e.g. immunohistological), sample location, size, bisection recommendations
   2. Indications: Conditions where biopsy is helpful
      1. Bullous Pemphigoid
      2. Dermatitis Herpetiformis
      3. Erythema Multiforme
      4. Lichen Planus
      5. Cutaneous T-Cell Lymphoma (Mycosis Fungoides)
      6. Psoriasis
      7. Rocky Mountain Spotted Fever
      8. Staphylococcal Scalded Skin Syndrome
      9. Subacute Cutaneous Lupus Erythematosus
      10. Sweet Syndrome
      11. Stephens-Johnson Syndrome (Toxic Epidermal Necrolysis)
7. References
   1. Ely (2010) Am Fam Physician 81(6): 726-34
   2. Ely (2010) Am Fam Physician 81(6): 735-9