Neuropathy Dermatitis

Presented by Professor Khalifa Sharqie
Chief of Dermatology
University of Baghdad, Iraq

Abstract:  Sixty year-old woman with neuropathy dermatitis at the right side of incision scar following right knee-joint replacement.

History: This 60 year-old woman had a right knee joint replacement on 7 Jan 2010. About three months post-op, she noticed non-itchy rash on the right side of the incision scar which has gradually enlarged in size. No other important medical history.

O/E:  I saw the patient on 9 June 2010 with the slightly scaly erythematous rash forming a plaque on the front of the right knee joint, on the right side of the incisional scar only.   It does not cross to other side.  The rash is completely anesthetic as confirmed by neurological assessment, while there is normal sensation on the left side of the scar.

Clinical Photo:

Diagnosis: Neuropathy dermatitis

Comment and question: This is similar to post-bypass dermatitis along one side of the saphenous vein harvesting scar on the front of the leg at the site of sensory neuropaphy. This rash also does not cross to the other side.  The present case seems to confirm that many skin diseases might follow the course of neuropathy like vitiligo and dermatitis.

I would like to ask my colleagues about any similar observations simulating the present case and await their fruitful comments.

References:
1. Sharquie KE. Post-Bypass dermatitis.  October 10, 2009 VGRD Blog

2. Logue EJ 3rd, Drez D Jr. Dermatitis complicating saphenous nerve injury after arthroscopic debridement of a medial meniscal cyst.  Arthroscopy. 1996 Apr;12(2):228-31
Abstract:  We report the case of a patient who developed hypesthesia in the distribution of the saphenous nerve after an arthroscopic debridement of a medial meniscal cyst. Dermatitis developed in the area of the hypesthesia 3 months later, Both complications responded to symptomatic treatment. A review of the literature confirms the unusual nature of these complications.

3. Satku K, Fong PH, Kumar VP, Lee YS. Dermatitis complicating operatively induced anesthetic regions around the knee. A report of four cases. J Bone Joint Surg Am. 1993 Jan;75(1):116-8.  No Abstract available

4. Mathias CG.  Post-traumatic eczema.  Dermatol Clin. 1988 Jan;6(1):35-42.
Abstract:
Thirteen cases of eczema that followed acute cutaneous trauma were observed. On the basis of the present case series, the following conclusions may be drawn: 1. Cutaneous trauma may precipitate eczema. 2. The trauma is sufficient to cause obvious tissue damage accompanied by an inflammatory or regenerative response. 3. Eczema usually begins within a few weeks of acute injury at the site of the cutaneous trauma. 4. Eczema may occur as an isolated idiopathic reaction or as an isomorphic reaction either preceding or following the appearance of an endogenous eczematous condition in nontraumatized skin. 5. Individual lesions of post-traumatic eczema may persist or recur for long periods of time. 6. The occurrence of post-traumatic eczema following occupational injury has important medicolegal implications.

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35 yo woman with short history of urticarial vasculitis

Abstract: 35 yo woman with three day history of an atypical urticarial eruption

HPI: This 35 yo woman developed an urticarial eruption 8 - 10 days after starting amoxicillin for a dental infection.  At first the lesions blanched with pressure but over the last few days before her office visit the some of the lesions looked hemorrhagic.  She had mild arthralgias but no fever or malaise.

O/E: There was a wide-spread eruption mostly on legs and arms.  On her thighs the lesions appeared hemorrhagic.  The torso, head and neck were mostly spared.

Clinical Photos:

Pathology:  Two 4 mm punch biopsies were obtained from the thighs.  There was a superficial and mid dermal mixed inflammatory infiltrate composed mostly of neutrophils and eosinophils with a few lymphocytes.  The pathology was read as leucocytoclastic vasculitis vs. urticarial vasculitis.
Photomicrographs are 10x, 20x, 40x and courtesy of Dr. Jag Bhawan

Lab:  CBC nl; Chem panel nl; UA nl

Diagnosis:  Most consistent with Drug-Induced Urticarial Vasculitis (UV).

Discussion:  While UV is recognized to present as a cutaneous drug eruption, MEDLINE has no reports of UV from amoxicillin.  In this otherwise healthy woman, this seems to be the best diagnosis.  She was treated with prednisone 20 mg b.i.d. and at one week her skin lesions had completely resolved.  The dose was dropped to 20 mg per day for the second week and then she will stop.  We are aware of cases of presumably drug-induced UV which can last for weeks to months and be associated with hypocomplementemia and positive ANA and antihistone antibodies. Since this woman did well and her process resolved quickly more specialized tests were not done.

Questions:
I don't feel any further work-up is indicated at this point.  If she stays clear the case is probably closed.  If she continues to have UV-like lesions once prednisone is discontinued, a more in-depth work-up will be initiated.  Does anyone feel we should be more aggressive?

Reference:
1. eMedicine.com  Urticarial Vasculitis
2. There are no reports of UV from amoxicillin and only one with ampicillin but it is very vague.

Note:  I will ask the patient to add her comments.