Metabolic epidermal necrosis

18 Metabolic epidermal necrosis

INITIAL PRESENTATION

Erythema, crusting, exudation and fissuring associated with hepatic disease in a dog.

INTRODUCTION

Metabolic epidermal necrosis (MEN), also known as superficial necrolytic dermatitis, necrolytic migratory erythema and hepatocutaneous syndrome, is a cutaneous reaction pattern associated with systemic disease. In dogs it has been associated with hepatic disease (cirrhosis, neoplasia and hepatitis), glucagon-secreting pancreatic tumours, with antiepileptic drugs such as phenytoin and phenobarbitone, and with mycotoxins. In humans, it is mostly associated with glucagon-secreting pancreatic tumours, although it may also be found in patients with liver cirrhosis or celiac disease. Recently, MEN has been subdivided into those cases associated with hepatic dysfunction and without a pancreatic tumour (MEN-HS), cases associated with a glucagon-secreting pancreatic syndrome (MEN-GS), and cases where there are raised liver enzymes, but the presence of a pancreatic tumour is not conclusively ruled out (MEN-ND).

CASE PRESENTING SIGNS

An 11-and-a-half-year-old, spayed cross-breed was presented with facial and pedal dermatitis and lameness.

CASE HISTORY

Duration of the condition at presentation is usually a few days to a few weeks. Most cases present with progressive skin lesions consisting of erythema, crusting and scaling over pressure areas and, frequently, lameness. These symptoms are poorly responsive to any treatment although there may be temporary improvement with antimicrobial therapy. There may be a history suggestive of systemic involvement with lethargy and perhaps anorexia. There may be gastrointestinal signs associated with hepatic dysfunction and many dogs develop concurrent diabetes mellitus resulting in polyuria and polydipsia. Pruritus is uncommon, but owners may report that the dog is foot licking.

The relevant history in this case was:

• The dog was in pain and was reluctant to walk.

• There was a poor response to non-steroidal analgesia (carprofen) and antibiotic treatment.

• The dog showed reduced appetite.

• Polydipsia without polyuria was observed.

• Pedal lesions had developed rapidly, and consisted of erythema, crusting and exudation on the plantar aspects of the feet, associated lameness and a reluctance to walk. Similar changes had developed over the elbows and the lip margins within a few weeks of the onset of the foot lesions.

• The dog had been fed on proprietary commercial canned and dried food since puppyhood. The food was stored in a dry environment and there had been no signs of mould growth on the food.

• The in-contact dogs were not affected.

CLINICAL EXAMINATION

General examination may reveal hepatic enlargement and abdominal pain, or may be unremarkable. A cutaneous examination usually reveals symmetrical facial and pedal distribution of lesions. Other areas of friction are commonly affected, and in some cases lesions on the ventral abdomen and other mucocutaneous sites may develop as the condition advances. Lesions usually consist of thick adherent crusts, erythema, exudation, erosions, ulceration and fissuring. The footpads are almost always involved, with lesions ranging from mild to severe hyperkeratosis, erosions and fissuring. Lesions on the ventral abdomen resemble target lesions, with a central area of hyperpigmentation surrounded by crusts and scale which can progressively coalesce to involve large areas. Often, secondary bacterial and Malassezia colonization is also reported.

In this case the relevant findings on clinical examination were:

• Anterior abdominal discomfort was noted during a general examination.

• There was a symmetrical distribution of lesions affecting the commissures of the lips, lateral aspects of the elbows and the feet.

• Detailed examination revealed marked erythema and exudation of the plantar skin, mild crusting on the margins of the pads, and erosion and fissuring of the pads themselves (Fig. 18.1).

• Paronychia was evident on some of the digits (Fig. 18.2).

• Crusting and scaling lesions were also present on the elbows (Fig. 18.3) and the lip commissures.

Figure 18.1 Erythema, fissuring, depigmentation, crusting and exudation on the foot.

Figure 18.2 Pus, erythema and swelling on the digit.

Figure 18.3 Scaling and hyperkeratosis on the elbow.

Tags: Saunders Solutions in Veterinary Practice Small Animal Dermatolo

Sep 3, 2016 | Posted by admin in SMALL ANIMAL | Comments Off

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