Download juvenile cellulitis

JUVENILE CELLULITIS
Elizabeth Toops, BS, DVM
Resident, Dermatology
Robert Kennis, BS, DVM, MS, DACVD*
Associate Professor, Dermatology
Douglass K. Macintire, DVM, MS, DACVIM, DACVECC†
Professor
Department of Clinical Sciences
Auburn University
C
anine juvenile cellulitis is a rare disorder primarily seen in puppies. It presents as an edematous vesiculopustular dermatitis that mainly
affects the face, pinnae, and submandibular lymph
nodes. The cause of this disorder is unknown but is
suspected to have a hereditary component. Infectious
agents, including bacterial agents and viral agents
such as distemper virus and herpesvirus, have been
considered as causes. However, the lesions are usually sterile, and, often, resolution of disease is much
slower with antibiotics alone than with antibiotics
and glucocorticoids. Also, special stains and electron
microscopy have failed to demonstrate microorganisms. Inoculation of tissue from infected dogs into
neonatal pups has not produced disease.
Another theory is that juvenile cellulitis is a hypersensitivity reaction, but this, too, is doubtful as treatment of most hypersensitivity disorders requires
allergen elimination or lifelong antiinflammatory or
immunosuppressive drug therapy. However, the proposed hypersensitivity reaction may be only temporary
in nature in young, growing puppies, which may
explain why most cases need only a transient course of
immunosuppressive treatment. Other potential causes
that have been suggested include poor hygiene, inadequate nutrition, endoparasites, stress, and a reaction
to vaccination. As this disease is characterized by a
significant positive response to glucocorticoids, there
is likely an underlying immune dysfunction.
Breed Predisposition
• Any breed can be affected, but dachshunds, golden
retrievers, Labrador retrievers, Gordon setters, beagles, and pointers may be predisposed.
• A high incidence of this disease process has been
shown to occur in Gordon setters. It has been
reported that approximately 25% of puppies from
affected litters had juvenile cellulitis.
Owner Observations
• The owners first notice facial swelling, mainly
around the eyelids, lips, muzzle, and pinnae.
• This progresses quickly within 24 to 48 hours to the
development of papules and pustules all over the
face. The face may become painful.
• An owner may also notice that the puppy is anorectic, lethargic, febrile, and has joint pain.
DIAGNOSTIC CRITERIA
Other Historical Considerations/Predispositions
• As heredity is implicated in the etiology, it is important to ask if other puppies in the litter have been
affected.
Historical Information
Physical Examination Findings
Gender Predisposition
• There appears to be no gender predisposition.
However, a UK survey reported a higher incidence
of this disease in male Gordon setters. Also, a
recently published retrospective study found that of
18 dogs with juvenile cellulitis, 67% were male.
• Edematous muzzle, lips, and eyelids. The swelling
is bilaterally symmetric.
• Prominent submandibular lymphadenopathy.
• Within 24 to 48 hours, bilaterally symmetric erythema, papules, vesicles, and pustules develop on
the lips, muzzle, chin, bridge of the nose, pinnae,
and periorbital regions.
• Frequently, alopecia and crusting develop in
swollen areas.
*Dr. Kennis discloses that he has received financial support
from Bayer Animal Health and Pfizer Animal Health.
†
Dr. Macintire discloses that she has received financial support from IDEXX.
6
Age Predisposition
• Occurs most commonly in puppies between the
ages of 3 weeks and 4 months.
• Has been documented in a dog 8 months of age
and suspected in two adult dogs (one was 2 years of
age and the other was 4 years of age).
A U G U S T
2 0 0 8
V
O
L
U
M
E
1
0
.
7
• Lesions may worsen and drain a serous to purulent
exudate.
• The swollen areas are not pruritic but are often
painful.
• A pustular otitis may occur, and the pinnae may
swell.
• Firm to fluctuant subcutaneous nodules that may be
painful or fistulate may occur around the anus, on
the prepuce, and on the trunk.
• A regional to diffuse lymphadenopathy may be
present.
• Puppies that are severely affected may be lethargic,
anorectic, and febrile and may have joint pain.
• Swollen paws rarely occur.
• If treatment is delayed, cicatricial (symmetrical scarring) alopecia may result.
• In some atypical cases, only the pinnae and ear
canals are affected.
Laboratory Findings
• Cytology of skin or ear exudate: purulent to pyogranulomatous inflammation. A secondary infection with bacteria or yeast may be identified. $
• Cytology of lymph node aspirate: suppurative, pyogranulomatous, or granulomatous inflammation.
No microorganisms are seen. $
• Dermatohistopathology: Ideally, biopsy samples
should be obtained from early, intact pustules, vesicles, or nodules. A punch biopsy of 4 to 6 mm is
usually sufficient. Larger punches and wedge biopsies can result in larger lesions that are more difficult to close as the tissue may be friable. $
— Epidermis: May be normal, hyperplastic, ulcerated, or contain pustules.
— Dermis: Usually multiple discrete or confluent
granulomas and pyogranulomas. These granulomas and pyogranulomas have clusters of
epithelioid macrophages with cores of neutrophils. They may also be pustular and suppurative. Several neutrophils may be seen in
the superficial dermis and extend into and
around follicles.
— Pyogranulomas may extend to the panniculus
and to the subcutis. Suppurative inflammation
may also extend to the subcutis.
— Chronic lesions may show scarring, especially
within the subcutis.
— Infectious agents are not seen.
• Bacterial cultures are normally sterile but can be
positive if secondary infections are present; coagulase-positive staphylococci are most commonly isolated. $
STANDARDS
of CARE: E M E R G E N C Y
Other Diagnostic Findings
• Chemistries and complete blood counts are not routinely conducted. However, some abnormalities have
been noted:
— Chemistry: Total serum globulin levels are normal. Hypoalbuminemia, elevated bile acid levels, and elevated alkaline phosphatase levels
have been reported. $
— Complete blood count: A normocytic, normochromic anemia, leukocytosis with neutrophilia,
and monocytosis have been reported. $
Summary of Diagnostic Criteria
• If the dog is between 3 weeks and 4 months of age
and presents with the facial signs listed in the physical examination section, juvenile cellulitis will be a
top differential.
• Once the basic cytology has been completed, it is
very important to obtain biopsy samples to confirm
the diagnosis of juvenile cellulitis.
Diagnostic Differentials
• Bacterial pyoderma (can resemble chin pyoderma
or deep pyoderma):
— Cytology should be conducted on samples
from intact pustules or from under crusts to
look for bacterial infection. Bacteria may be
found with secondary infection in cases of
juvenile cellulitis. $
— Culture of tissue samples collected by surgical
prep can also rule out infection. $
• Demodicosis: Deep skin scrapings should be performed on lesional skin. $
• Dermatophytosis:
— Hair and crust should be tested on dermatophyte test medium. $
— A trichogram (examination of hair under a
microscope) may be conducted looking for
evidence of arthroconidia (including ectothrix
and endothrix spores and hyphal invasion of
hairs). If arthroconidia are not found along the
hair shaft, this does not rule out dermatophytosis. $
• Angioedema: Dermatohistopathology of biopsy
samples should help to rule this out. $
• Adverse cutaneous drug reaction: The owner
should be questioned about recent administration
of medications (including routine vaccinations).
Dermatohistopathology of biopsy samples should
help to rule this out. $
• Distemper: Although distemper is a diagnostic differential and has been considered in the etiology of
juvenile cellulitis, it is not currently thought to be
the main cause of this disease. Distemper is much
7
AND
CRITICAL
CARE
MEDICINE
less common in vaccinated puppies and is usually
more of a consideration once other disease
processes such as juvenile cellulitis have been ruled
out. Distemper often causes hyperkeratosis of digital pads. This is not commonly seen in juvenile cellulitis. Dermatohistopathology should help to rule
out distemper. It is not necessary to pursue polymerase chain reaction of body fluids (i.e., serum
and cerebrospinal fluid) or immunohistochemistry
to detect distemper antigen unless this disease is of
higher concern. $
Alternative/Optional
Treatments/Therapy
• Griseofulvin 14–34 mg/kg PO q24h. No required
length of treatment has been reported. Recently
studied cases in which this drug was administered
showed resolution within 3 weeks. We are not
aware of any confirmed juvenile cellulitis cases that
did not respond to appropriate glucocorticoid treatment. However, griseofulvin is thought to work via
its immunomodulatory properties.
Supportive Treatment
TREATMENT
RECOMMENDATIONS
Initial Treatment
• Early, aggressive therapy is indicated.
• Immunosuppressive dosages of glucocorticoids are
the main treatment of choice. Prednisone or prednisolone should be administered at 2 mg/kg PO
q24h until clinical resolution of signs occurs, which
usually takes 1 to 4 weeks. After signs have resolved,
the dosage should be tapered gradually by giving 2
mg/kg PO q48h for approximately 2 weeks and then
tapering completely over the next 2 weeks. Cases
with panniculitis may require a longer course of
treatment. $
• Some dogs respond better to dexamethasone at 0.2
mg/kg PO q24h. This should be tapered in a similar
fashion to prednisone or prednisolone. $
• Initiation of antibiotic therapy is recommended
regardless of whether there is evidence of secondary infection. Dogs receiving immunosuppressive
dosages of glucocorticoids are more prone to developing a secondary infection.
— Cephalexin is a good choice. The suggested
dosage is 22–30 mg/kg PO q24h 1 week beyond
remission of clinical signs. $
— Amoxicillin–clavulanate is another appropriate
antibiotic choice. The suggested dosage is
13.75 mg/kg PO q24h 1 week beyond remission of clinical signs. $
• Daily topical therapy using warm water to remove
crusts may be of benefit. This may not be tolerated
by young puppies.
• A mild hypoallergenic shampoo may also be instituted to help remove crusts. This should not be
applied more often than twice weekly. This may
not be tolerated by young puppies. As many
lesions are around the face, owners must be told
to be careful with application and to apply a sterile ophthalmic lubricant in each eye before
bathing. $
8
A U G U S T
2 0 0 8
V
O
L
U
M
E
1
0
.
7
• It is very important to ensure that the puppy is
obtaining adequate nutrition during this period of
growth. This may be more of a concern in patients
presenting with inappetence. $
• Often, these patients are very painful. In these
cases, a short-term (1 to 3 days) course of a pain
medication such as tramadol may be appropriate.
The suggested dosage is 1–4 mg/kg PO q8–12h. $
Patient Monitoring
• Normally, the patient improves rapidly. The veterinarian or a technician should talk with the owners
every 2 to 3 days for an update. If the patient worsens, reassessment is necessary. If treatment is going
well, it is appropriate to recheck 2 to 3 weeks from
the initial visit so that medications may be adjusted.
Also, because the patient may be growing quickly
during this time period, dosages may need to be
increased accordingly.
Home Management
• It is crucial for owners to follow the medication regimens indicated by their veterinarians.
• If signs worsen, the owner should notify the veterinarian in case another problem is occurring.
Milestones/Recovery Time Frames
• Generally, facial lesions should begin to resolve
within 1 to 3 days of beginning corticosteroid treatment. Lameness, fever, and appetite should greatly
improve or resolve by this time.
• All lesions should resolve within 1 to 4 weeks of
treatment. Treatment may take longer if the panniculus is affected. Scarring alopecia may remain if treatment was started later in the course of the disease.
Treatment Contraindications
• NSAIDs should not be used for pain management as
they are contraindicated with concurrent glucocorticoid therapy.
• Tramadol is contraindicated in severely debilitated
patients.
• Other immunosuppressive agents, such as cyclosporine, are not indicated for this disease process.
regarding applicability. Subscribers may take individual CE tests online and get real-time scores free
of charge at SOCNewsletter.com.
PROGNOSIS
Favorable Criteria
• Prognosis is good if treatment is instituted within 4
to 5 days. However, treatment started later can often
have favorable results.
• Relapses are very uncommon.
• Rarely, this disease spontaneously resolves.
1. What are common physical examination findings
of juvenile cellulitis?
a. crusting of the face and interdigital spaces
b. bilateral edematous swelling of the muzzle, lips,
and eyelids
c. alopecia of the pinnae and trunk
d. swollen conjunctiva and tearing
Unfavorable Criteria
• If any secondary infection is present, it must be
addressed because immunosuppressive dosages of
glucocorticoids can lead to worsening of infectious
diseases.
• If treatment is delayed, permanent scarring can
occur.
• With no treatment, death can occur or euthanasia
may be recommended because of pain, a poor
quality of life, or the presence of secondary infections.
RECOMMENDED READING
Bassett RJ, Burton GG, Robson DC. Juvenile cellulitis in an 8-monthold dog. Aust Vet J 2005;83(5):280-282.
Gross TL, Ihrke PJ, Walder EJ, Affolter VK. Skin Diseases of the Dog
and Cat: Clinical and Histopathological Diagnosis. 2nd ed.
Oxford: Blackwell Science Ltd; 2005:327-329.
Mason IS, Jones J. Juvenile cellulitis in Gordon setters. Vet Rec
1989;124:642.
Medleau L, Hnilica KA. Small Animal Dermatology: A Color Atlas
and Therapeutic Guide. 2nd ed. St Louis: Elsevier; 2006:284286.
Neuber AE, Van Den Broek AHM, Brownstein D, et al. Dermatitis
and lymphadenitis resembling juvenile cellulitis in a four-yearold dog. J Small Anim Pract 2004;45:254-258.
Scott DW, Miller WH. Juvenile cellulitis in dogs: a retrospective
study of 18 cases (1976–2005). Jpn J Vet Dermatol 2007;13(2):
71-79.
Scott DW, Miller WH, Griffen CE. Muller & Kirk’s Small Animal Dermatology. 6th ed. Philadelphia: Saunders; 2001:1163-1167.
Shibata N, Nagata M. Efficacy of griseofulvin for juvenile cellulitis in
dogs. Vet Dermatol 2004;15(suppl 1):26.
CE ARTICLE #2 CE TEST
The Auburn University College of Veterinary Medicine approves this article for 1 contact hour of continuing education credit. Those who wish to apply
this credit to fulfill state relicensure requirements
should consult their respective state authorities
STANDARDS
of CARE: E M E R G E N C Y
2. Cytologic evaluation of exudate from the skin often
reveals
a. acantholytic cells.
b. abundant cocci and rods with no inflammatory
cells.
c. purulent to pyogranulomatous inflammation.
d. eosinophils and mast cells.
3. The most common differentials of this disease
include
a. demodicosis, bacterial pyoderma, and dermatophytosis.
b. demodicosis, pemphigus foliaceus, and discoid
lupus erythematosus.
c. bacterial pyoderma, yeast dermatitis, and
cheyletiella.
d. pemphigus foliaceus, adverse drug reaction, and
vasculitis.
4. What is the main treatment choice for this disease?
a. Corticosteroids at 0.5 mg/kg PO q24h until clinical resolution, then 0.5 mg every other day.
b. Corticosteroids at 2 mg/kg PO q24h until clinical
resolution, then taper over approximately 2 weeks.
c. Azathioprine at 2.2 mg/kg PO q24h until clinical
resolution, then taper over 2 to 4 weeks.
d. Cephalexin at 30 mg/kg PO q12h until clinical
resolution.
5. Which of the following is currently thought to be a
likely underlying cause of juvenile cellulitis?
a. staphylococcal pyoderma
b. mycobacterial infection
c. parvoviral infection
d. immune dysfunction
9
AND
CRITICAL
CARE
MEDICINE