Cytological evaluation of inflammatory and neoplastic skin disease PART 1

Inflammatory cells are usually neutrophils, eosinophils, macrophages, lymphocytes, plasma cells.

Pyoderma

Pyoderma

Eosinophilic plaque in a cat

Interdigital granuloma in a dog

Non-inflammatory cells:

- Epithelial cells: tend to exfoliate in high numbers are often present in cohesive clusters and sheets. Individual cells are round, cuboidal or polygonal. Most epithelial cells have well-defined cell borders. We see them on a regular basis in the inflammatory preparations, where they are admixed with bacteria, fungi and inflammatory cells. In non-neoplastic tumours we find them often in inclusion type cysts or cystic epithelial tumours. They should be evaluated for criteria of malignancy. 

Normal epidermal cells by layers

Squamous cell carcinoma

Basal cell tumor

- Mesenchymal cells (spindle cells):  Tissue cells tend to exfoliate in low numbers and are present in loose aggregates or groups. The cells are usually spindle shaped but can appear more ovoid and plump.  If these cells are contained in an inflammatory exudate they can become reactive and can mimic pleomorph neoplastic cells. Usually this is seen in granulation tissue. However, a high number of spindle-shaped cells are indicative of neoplasia. The origin is very difficult to detect, they can arise form adipose, fibrous, vessel, neural etc. tissue.

Lipoma

Liposarcoma

Spindle cell tumor of soft tissue origin

- Round-cells: Round-cell lesions tend to exfoliate readily, although cells can be fragile, requiring gentle preparation for cytology. Cells are discrete with well-defined cell borders. Common cells of this category include lymphocytes, histiocytes, mast cells, and plasma cells, as well as cells of transmissible venereal tumors.      
                                                                  

Histiocytoma

Plasmacytoma

Mast cell tumor

Lymphoma

Melanocytoma

Primary cornification disorders

The cornification process represents morphologic changes in the whole life span of the keratinocytes. It starts already in the basal cell layer keratinocytes and ends with the final differentiated corneocytes of the ‘strong and compact’ stratum corneum. The main functions of this layer are the toxin/microbe/trauma/UV light protection and prevention of fluid loss (skin hydration). Four key steps are included in these processes:

1.     Formation of the protein core (aggregation of keratins, with the help of fillagrin)

2.     Formation of the protein envelope (replacement of the previous cell membrane with a ‘stronger’ one consisting of small peptides)

3.     Formation of the lipid lamellar bilayers (consisting of cholesterol, long-chain fatty acids, and ceramides, important role of lamellar bodies)

4.     Desquamation (corneodesmosomes are cleaved by proteases, the corneocytes are shed into the environment)

Cornification disorders arise when there is a problem in establishing a normal stratum corneum. They are usually secondary, to an allergic, parasitic, metabolic, (para)neoplastic or endocrine disease. Primary cornification disorders, the so-called ichthyoses are due to a genetic defect somewhere in the cornification process or elements: structural proteins, lipid metabolism, enzymes. Some investigators include abnormalities in sebaceous gland function (eg, sebaceous adenitis, sebaceous gland dysplasia) as primary cornification disorders as well. The diagnostic approach involves thorough clinical assessment and ruling out secondary causes. Skin biopsies and genetic test are usually inevitable to make a final diagnosis.

Icthyosis resembles primary cornification disorders is at present subdivided into epidermolytic and non-epidermolytic forms on the basis of light microscopy.

1. Epidermolytic ichthyosis in the Norfolk terrier is autosomal recessive and caused by a mutation in epidermal keratin 10. It was also described in some other breeds (Rhodesian ridgeback). These dogs have multifocal areas of hyperpigmented hyperkeratosis (intertriginous areas) and dark scaling. The skin is sensitive to mechanical trauma (erosions).

2. Non-epidermolytic

This group is corresponding to the autosomal recessive congenital ichthyosis (ARCI) in humans, which is the official classification for a heterogeneous group of disorders with overlapping phenotypes (e.g. lamellar ichthyosis, congenital ichthyosiform erythroderma). A variety of mutations affecting lipids and structural proteins cause similar phenotypes and light microscopic changes. In humans, there are currently 8 known mutations, in comparison researchers characterized 3 in veterinary medicine. The current nomenclature used by pathologists in veterinary medicine is to label these ARCI disorders by the breed predilection, as described bellow. We will se if this will change in the future.

Golden retriever ichthyosis

Golden retrievers may presents with usually mild-moderate non-pruritic generalised scaling (mild to moderate) disorder, in the age from 3 weeks to 3 years (85% before 1 year of age). In France a high prevalence (50%) was shown in this breed. The causing gene is now known to be PNPLA1 (belonging to the patatin-like phospholipase family). It is coding for a protein responsible for lipolytic and/or lipogenic activity of neutral lipids (not triglycerides). These studies in dogs helped to reveal the cause also in human patients with ARCI. In non-breeding animals a diagnosis based on clinical and histopathological findings is sufficient. Performing a genetic test (www.antagen.com) in breeding animals to assess carrier state is recommended.

American Bullterier ichthyosis

American bulldogs typically have a more severe phenotype (then Golden retrievers) with lesions evident before weaning (sometimes shortly after birth). The scaling is generalized (also in the coat) with large, light brown adherent scale on the ventral thorax and abdomen, the skin is often erythematous. The abdominal skin of adult dogs may be reddish-brown. The animals may show otitis, pododermatitis and intertrigo. Secondary Malassezia infections may develop and be associated with a significant pruritus. Pedigree analyses are highly suggestive of an autosomal recessive trait and the responsible gene is coding for the protein ICHTHYN. The test can be performed at The University of Pennsylvania USA (dogderm@vet.upenn.edu)

Jack (Parson) Russel Icthyosis

The clinical lesions are characterized by thick, adherent scales (0,5 -2 cm large) predominantly on ventral skin areas (abdomen, ventral neck). The skin of the food pads and nose may be thickened and greasy. The dogs may develop severe secondary yeast and/or bacterial infections with corresponding inflammation and pruritus. Nonepidermolytic ichthyosis in Jack Russell terriers (JRT) is caused by a loss of function mutation in transglutaminase 1 (TGM1). TGM1 mediates calcium dependent cross-linking of peptides (e.g. involucrin, loricrin) to form the cornified envelope- the strong exterior of the corneocyte.

Non-determined cornification disorders

Some other breeds are described with clinical signs of ichthyosis, but the molecular characterization is not available yet. The following breeds are mentioned: Cavalier King Charles spaniel dogs (keratoconjunctivitis starting from eyelid opening age, a roughened/curly haircoat, scaling with abdominal hyperpigmentation, footpad hyperkeratosis, and nail dystrophy), West Highland White terriers, soft-coated Wheaton terrier.

Unconfirmed cornification disorders

For some diseases, there is lack of sufficient evidence that they are a primary cornification disorders. Vitamin A – responsive dermatosis, generalized sebaceous gland hyperplasia and primary seborrhea are in this moment controversial diseases.

References

- Barnhart KF et al. A heritable keratinization defect of the superficial epidermis in norfolk terriers. J Comp Pathol. 2004 May;130(4):246-54.

- Credille KM. Transglutaminase 1-deficient recessive lamellar ichthyosis associated with a LINE-1 insertion in Jack Russell terrier dogs. Br J Dermatol. 2009;161(2):265-72.
- Credille KM et al.  Mild recessive epidermolytic hyperkeratosis associated with a novel keratin 10 donor splice-site mutation in a family of Norfolk terrier dogs. Br J Dermatol. 2005 Jul;153(1):51-8.
- Grall A et al. PNPLA1 mutations cause autosomal recessive congenital ichthyosis in golden retriever dogs and humans. Nat Genet. 2012;44(2):140-7
- Guaguere E et al. Clinical, histopathological and genetic data of ichthyosis in the golden retriever: a prospective study. J Small Anim Pract. 2009;50(5):227-35
- Lewis et al. Characterization and management of a Jack Russell terrier with congenital ichthyosis. Vet Dermatol 1998; 9(2) pages 111–118.

- Mauldin E. Proceedings of the 27th Annual congress of the ESVD-ECVD 2014, p.124-127
- Mauldin EA. Canine ichthyosis and related disorders of cornification. Vet Clin North Am Small Anim Pract. 2013 ;43(1):89-97
- Mauldin EA et al. The clinical and morphologic features of nonepidermolytic ichthyosis in the golden retriever. Vet Pathol. 2008;45(2):174-80.

NOVOST Journal club za člane - Februar 2015

Dragi člani, se želite udeležiti interaktivne diskusije preko skypa?

Kdaj: Februar 2015: torek, sreda ali četrtek 10., 11 ali 12. ob 20h
Trajanje: max. 1,5h

Tema: Spodnji članki, vaši klinični primeri, razna dermatološka vprašanja

(članke ste dobili po emajlu, ali pa predstavite članek po vašem okusu).

Potrditev udeležbe: na elektronsko doodle anketo (vpišite kar svoje skype ime)

http://doodle.com/6u8cm6vw7v3rrf9p

ali pa na emajl : ana_rostaher@yahoo.com

Lista člankov

1. Urticarial vasculitis in a French bulldog. Declercq J Vet Dermatol. 2015 Feb;26(1):72-3.

2. Feline leishmaniosis: a case with a high parasitic burden. Migliazzo A et al.

Vet Dermatol. 2015 Feb;26(1):69-70.

3. Concurrent Bartonella henselae infection in a dog with panniculitis and owner with ulcerated nodular skin lesions. Rossi MA et al. Vet Dermatol. 2015 Feb;26(1):60-e22

4. A blinded, randomized clinical trial comparing the efficacy and safety of oclacitinib and ciclosporin for the control of atopic dermatitis in client-owned dogs. Little et al. Vet Dermatol. 2015 Feb;26(1):23-e8.

5. Efficacy of oclacitinib (Apoquel) compared with prednisolone for the control of pruritus and clinical signs associated with allergic dermatitis in client-owned dogs in Australia

Caroline Gadeyne et al Vet Dermatol. 2014 Dec;25(6):512-8,

6. Deslorelin for the treatment of hair cycle arrest in intact male dogs. Albanese et al. Vet Dermatol. 2014 Dec;25(6):519-22

Kratka navodila

Predstavitev publikacije naj obsega sledeče:

-       Povzetek v 1 stavku - bistvena ugotovitev članka

-       Namen raziskave ali oziroma zakaj je bil klinični primer predstavljen

-       Opis kliničnega primera oz. materialov in metod

-       Rezultati, če je študija oz. kaj se je dogajalo s kliničnim primerom

-       Diskusija (bistvene ugotovitve)

-       Kritična ocena članka (pozitivna in negativna)

Približno 10 minut, nato še diskusija.

  

Neonatalna in pediatrična veterinarska dermatologija

9. april 2015, Kongresni Center Bernardin, Portorož

Dermatološka veterinarska sekcija Slovenije Vas vljudno vabi na dermatološko poslastico: Dermatologija od novorojenčkov do 'mladostnikov'. Ta izredno pomembna tema je nekako pozabljena, če ne zanemarjena v dermatološki literaturi. Zato upamo, da bodo tokratna predavanja zapolnila manjkajočo vrzel in Vam posredovala uporabne informacije za vsakodnevno prakso. Predavatelj bo Dr. Jan Declercq, veterinar z desetletji kliničnih izkušenj in enim izmed največjih dosjejev nenavadnih, novih kožnih obolenj. Njegova predavanja so vedno polna zanimivih primerov in praktičnih 'dermatoloških instinktov', kako najenostavneje in elegantneje priti do diagnoze, ozdravitve in postavitve pravilne prognoze.

Udeležence vabimo tudi, da predstavijo lastne primere (slike so dobrodošle, kvaliteta ni pomembna).

Vljudno vabljeni!

Čas	Program
8.30 -	Registracija
9.30 – 11.00	Neonatalna in pediatrična dermatologija I (J Declercq)
11.00 – 11.30	Odmor
11.30 – 13.00	Neonatalna in pediatrična dermatologija II (J Declercq)
13.00 – 14.30	Kosilo
14.30 – 15.30	Diskusija primerov predavateljev in udeležencev (A Rostaher)
16.00 – 16.30	Odmor
16.30 – 17.30	Dermatologija mladih odraslih psov (J Declercq)
17.30 – 18.00	Letna skupščina

Uradno vabilo z informacijami glavnega kongresa in prenočišči  >>          Prijavnica >>
 

Življenjepis

Methicillin-resistant Staphylococcus pseudintermedius (MRSP) infections

Clinical signs

There are no clinical markers to distinguish between MRSP and MSSP. The clinical presentation is the same as for other pyodermas. We distinguish between:

·       Surface (intertrigo, ‘hot spots’)

·       Superficial (bacterial folliculitis, impetigo, muco-cutaneous pyoderma, superficial-spreading pyoderma)

·       Deep pyoderma (furunculosis, pododermatitis with granulomas, lick granuloma, callus pyoderma)

Lesions include: papules, pustules, erythema, hyperpigmentation, alopecia, scaling and collarets for superficial lesions and fistulas, nodules and bullae for deep infections. Additionally, MRSP can be found in otitis cases.

A resistant bacteria is usually suspected if:

·       The lesions improved less then 50% within 2 weeks of antibiotic treatment

·       If new lesions develop during antibiotic treatment

·       If despite 6 weeks of antibiotic treatment, lesions are still present

·       If intracellular rods are found on cytology

·       Prior history of drug resistant infection in the household pets

Diagnosis

A correct early diagnosis of a MRSP infection is essential, as one can then start implementing measures to prevent bacterial transmission to other beings and to the environment (MRSP can persist in the environment for months) and select the proper therapeutic regime. Before performing a culture, a cytological examination should be always performed to visualize the bacteria (rods, cocci) or other infectious agents (fungi). If the culture comes back negative, but we have seen bacteria in the cytology one has to repeat the cultures (if still clinical signs).

The material for the culture can be obtained with swabs (erosions, pustules) and skin biopsies if the lesions are deep (in this case the overlying surface should be disinfected and a 4-6mm punch taken, before putting the material in the culture medium, the intact epidermis should be eliminated to avoid surface contaminants).

The material should be sent to the lab, which then performs cultures and susceptibility tests (Kirby Bauer disc diffusion test and/or minimum inhibitory concentrations). To further characterize the bacteria and their resistance pattern, the following tests can be performed: PBP2a latex bead agglutination test, mecA PCR, SCCmec typing, D-test (for inducible clindamycin resistance), … If the animals were or are currently on antibiotics the lab should be informed about this situation and the used antibiotic, to implement measures to prevent false negative results (the lab can then enrich and/or prolong the cultures as the bacteria may be less ‘vital’ due to used antibiotics).

Treatment

The treatment follows the same principles as for susceptible infections. Its success depends on the bacteria (susceptibility), severity of lesions, pet and owner compliance and on the underlying primary disease.

It is important to eliminate the bacteria and prevent their spread as soon as possible, therefore a combination therapy consisting of shampoos (chlorhexidin, benzoyl peroxide, ethyl lactate) and systemic treatment should be combined whenever possible for generalized disease. For focal lesions antibacterial shampoos or creams (mupirocin, fucidic acid) can be used. Problems with topical therapy include poor owner compliance, poor penetrations in deeper tissues, biofilm formation and resistance.

The antibiotic use should depend on the sensitivity results, some MRSP are multi-drug resistant as they can acquire or express more then one resistance gene. Often MRSP maybe be susceptible to the following antibiotics: chloramphenicol, trimethoprim/sulfamethoxazole, amikacin, fucidic acid, doxycycline.

Antibiotics such as vancomycin, teicoplanin, linezolid are exclusively reserved for treatment of humans infected with multi-resistant MRSA.

Prevention

Each practice should utilize special prevention measures for cases of resistant infection (appropriate owner education, hygiene measures, restricted antibiotics use).

Zoonotic potential

There are reports of MRSP carriage in owners of dogs which were infected with MRSP (same strain) or in veterinarians and veterinary personnel. Human infections are very rare, but possible (attention to immune-suppressed animal owners and care-takers).

References

- Linek M. Proceedings of the 27th Annual congress of the ESVD-ECVD 2014, p114-118.

- Hillier A et al.  Guidelines for the diagnosis and antimicrobial therapy of canine superficial bacterial folliculitis (Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases). Vet Dermatol. 2014 Jun;25(3):163-75

-  Beco L et al. Suggested guidelines for using systemic antimicrobials in bacterial skin infections (1): diagnosis based on clinical presentation, cytology and culture. Vet Rec. 2013 Jan 19;172(3):72-8.

-  Beco L et al. Suggested guidelines for using systemic antimicrobials in bacterial skin infections: part 2 antimicrobial choice, treatment regimens and compliance. Vet Rec. 2013 Feb 9;172(6):156-60

- Bannoehr J, Guardabassi L. Staphylococcus pseudintermedius in the dog: taxonomy, diagnostics, ecology, epidemiology and pathogenicity. Vet dermatol 2012 Aug;23(4):253-66