Laboratory Data

Two 4 mm punch biopsies were taken. Dr. HR Byer M.D., Skin Pathology Laboratory, Boston University, Boston, USA

The biopsies from the plaque and nodule show similar findings. These are:
• Parakeratosis, a flattened epidermis and basal cell layer vacuolization.
• Squamatization of the basal cell layer
• Necrotic keratiocytes
• Moderate to dense superficial and deep perivascular infiltrate

The differential diagnosis includes: chilblain lupus. It is interesting that a biopsy of dermis is sufficient for the diagnosis of ECP and does not require "panniculitis" given the clinical history. Nonetheless, in this case there is some inflammation identified in the fat around the eccrine glands.

4X Superficial

4X Deep

20X Superficial

20X Deep

Equestrian Cold Panniculitis

The next morning after seeing the patient I searched PubMed with various terms such as "horse," "panniculitis," "perniosis" and came up with "Equestrian Cold Panniculitis in Women."

Had I known of this reference, the biopsy would have not been necessary. There are scant therapeutic guidelines save for keeping areas warm. Interestingly, patients with ECP are reluctant to change their riding habits.

The patient was seen in follow-up at one week. She's been careful to wear long. thermal underwear while outside working with and riding the horses. Everything resolved in a few days except for the superficial erosions which were less prominent. The areas which were cool to the touch on the previous visit were now normal temperature to palpation.

Note resolution of nodules and residual erosions. "Xs" are at sites of biopsies.

2. Equestrian Cold Panniculitis at the Virtual Rounds in Dermatopathology

Ian McColl MBChB, FACD,Consultant Dermatologist, John Flynn Medical Centre, Tugun, Queensland, Australia on Jan 1, 2008

The distribution of the rash in this condition is due to the insulating properties of fat. The skin is cooled excessively because heat cannot transfer easily through the fat from the warmer underlying core. Lesions commonly occur on the buttocks and over fat upper arms in horse riders. Jockeys do not get it because they are not fat!

Henry Foong FRCP, Ipoh, Malaysia on Jan 1, 2008

Thanks for presenting this interesting case. I have not heard of this entity before and it is certainly a great teaching case. The lobular panniculitis histology was very impressive.

Robert Rudolph MD, FACP, Clinical Professor of Dermatology, University of Pennsylvania, Philadelphia, PA, USA on Jan 1, 2008

Terrific and instructive case. Great way to start the New Year!!

Joel Bamford M.D., Duluth, MN, USA on Jan 2, 2008

Thanks for making me aware of Equestrian Cold Panniculitis in women.

Arash Abtahian M.D. Shiraz, Iran on Jan 2, 2008

ECP is a variant of perniosis being in proximal lower extremities. It occurs in person riding horses and does not wear warm clothings. Treatment is the same as perniosis

Khalifa Sharquie MD, Professor of Dermatology, College of Medicine, University of Baghdad, Baghdad, Iraq on Jan 3, 2008

Although it is an interesting case but perniosis and cold panniculitis probably represent extremes of one spectrum that occur in cold countries like Iraq which is now a common problem and there should be no problem in diagnosis. It could be easly prevented by avoidance of cold exposure with supportive therapy like topical and systemic steroids

Bushan Kumar MD, Former Head of Dermatology, Postgraduate Institute of Medical Education & Research, Chandigarh, India on Jan 3, 2008

Lesions of perniosis or chilblains are known to occur on the parts of the body like fingers, toes, nose and ears which cannot be considered as having a lot of fat and normally there is good amount of circulation in these parts either because of anatomical location or because of their participation in normal activities. The lesions tend to occur because of cold induced vasoconstriction. I am not sure if the layer of fat facilitates the development of lesions by obstructing the transmission of heat from the circulation below or it acts as a insulation against damage due to cold.