UMEM Educational Pearls - Dermatology

Title: Toxicodendron dermatitis

Category: Dermatology

Keywords: Toxicodendron dermatitis, treatment (PubMed Search)

Posted: 6/19/2010 by Michael Bond, MD (Updated: 11/22/2024)
Click here to contact Michael Bond, MD

Toxicodendron dermatitis:

This is the contact dermatitis caused by the plant genus Toxicodendronm, better known as Poison Ivy.  Here are some types to prevent the dermatitis and how to treat it:

  1. Barrier products like Ivy Block® are on the market that go on like suntan lotion and provides a protective barrier on your skin that prevents the plants urushoil, the toxin responsible for the dermatitis, from making contact with your skin. This can help prevent the dermatitis if you are able to wash the oils off.
  2. Most soaps can not remove urushiol and may actually increase its spread. Several products are on the market, one being Zanfel® , that are a little more effective than water in removing the urushiol which can help to minimize the dermatitis and its spread.
  3. The mainstay of treatment is systemic steroids.  This condition does not do well with a short (5 day) burst therapy and patients will typically get a rebound dermatitis when the burst is complete.  Patients should be placed on a 14 day steroid taper.

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Title: Pityriasis Rosea

Category: Dermatology

Keywords: Pityriasis rosea (PubMed Search)

Posted: 1/3/2010 by Michael Bond, MD
Click here to contact Michael Bond, MD

Pityriasis Rosea

  • A common exantham that typically presents initially with a herald patch, followed by a generalized rash over the next 1-2 weeks and can last 4-6 weeks.
  • Patients may initially have prodromal symptoms such as joint pain,headache, fever and malaise that precede the appearance of the rash.
  • The primary plaque, herald patch, is seen on the skin in 50-90% of cases.
  • The generalized rash typically develops in crops along the lines in the skin leading to a characteristic "Christmas tree" pattern.
  • Pruritus is present in 75% of cases.
  • Usually a self-limited, benign illness that does not require any treatment.  Though symptomatic treatment of the pruritus is reasonable.


Title: Nikolsky's sign

Category: Dermatology

Keywords: Nikolsky's sign, Dermatology (PubMed Search)

Posted: 12/26/2009 by Michael Bond, MD (Updated: 11/22/2024)
Click here to contact Michael Bond, MD

Nikolsky's sign is positive when slight rubbing of the skin results in exfoliation of the skin's outermost layer.  The more technical term is acantholysis which is the loss of the normal adhesion of the epithelial skin cells which allows for this sloughing.

Seen in:

  • Toxic Epidermal Necrolysis
  • Pemphigus vulgaris
  • Scalled Skin Syndrome
  • Bullous impetigo
  • Epidermolysis bullosa

Often helpful to differentiate pemphigus vulgaris from bullous pemphigoid. The sign is usually absent in bullous pemphigoid.  Just be careful with how much testing you are doing as this can be very painful to the patient.