63 (134)

6

Diagnosis

The diagnosis is based on appearance of the lesions. The differential diagnosis includes other causes of paronychia (e.g. dermatophytosis, cryptococcosis, pemphigus foliaceus) and digital metastasis of a pulmonary adenocarcinoma.

Cytological examination of pus usually reveals evidence of colonisation by different types of bacteria.

Bacterial culture should be carried out routinely.

The underlying cause must always be looked for and identified.

Prognosis and treatment

The prognosis is always dependent on the underlying cause " ^l2.

Treatment is difficult. Surgical treatment involves ablation of the affected nails followed by twice daily antiseptic washes. Antibiotic therapy is the treatment of choice and should be based on antibiotic sensitivity testing. Fluoroąuinolones (e.g. enrofloxacin and marbofloxacin) are particularly indicated (Table 6:1). Duration of treatment has to be long, from several weeks to several months and must be continued for several weeks beyond resolution. Recurrence is common.

Acne

Aetiopathogenesis

Acne is a primary keratinisation problem, resulting in secondary infection of areas rich in sebaceous glands "³. Signs of acne are the same as those described for demodicosis, Malassezia dermatitis, even contact dermatitis (e.g. associated with plastic food bowl) or dermatophytosis^l3’¹⁴. Various bacteria, including Pasteurella multocida and beta-haemolytic streptococci, can be isolated from within infective foci¹³.

Clinical features

Dermatological signs are characterised by comedones, follicular casts (Fig. 6 : 4), papules, pustules and furuncles on the chin and sometimes the upper lip. Rarely, marked swelling of the chin is seen ¹³¹⁴. If comedones and follicular casts are present, acne should be considered, whereas if they are absent, an eosinophilic granuloma should first be suspected.

Diagnosis

The diagnosis is based on clinical examination and exclusion of other causes (demodicosis, Malassezia dermatitis, dermatophytosis) by appropriate diagnostic tests.

Cytological examination of pustular contents demonstrates varying numbers of intracellular and extracellular bacteria, degenerating neutrophils and macrophages '⁴.

Histopathological examination of skin biopsies reveals dilated, keratin-filled hair follicles, perifolliculitis, folliculitis and furunculosis. Marked fibrosis is often seen in chronic cases^l4.

Treatment

Appropriate systemie antibiotics are not always successful in treating acne ^,3. Clindamycin appears to us to be the antibiotic that gives the best results (Table 6:1). Treatment should be given for 4-6 weeks and continued for at least one week beyond clinical resolution.

Benzoyl peroxide shampoos (2%), applied 1 to 2 times daily, may give good results but care should be taken to rinse thoroughly in order to avoid possible local irritation ¹³.

Mupirocin gel (2%) is effective in the treatment of feline acne ^l4. This gel is used twice daily for 3-6 weeks. The lesions should not be licked for 5-10 minutes after application. Nephrotoxicity caused by the excipient polyethylene base is unlikely to develop provided only smali amounts of the product are applied each time.