History

Fact Explanation
Skin lesion Pseudocowpox or the "Milker's nodules" is a disease caused by Pseudocowpox virus of the genus Parapoxvirus. It produces mild infections of the teats of cows and ulcers in the mouths of calves. Human disease is contracted through direct transmission. Two weeks following the exposure to a infected cattle, patient develops small, red, raised, flat-topped spots. Within another week, they develop into slightly tender blisters or nodules (lumps). The top of the nodules often develops a grayish skin and a small crust. The nodules are usually on the hands, particularly the fingers, but occasionally the face. They are usually solitary and rarely can be numerous. The lesions may or may not be painful. [1,2,3]
Itch The pseudocowpox nodules sometimes may itch. [1]
Ulceration Central ulceration or crust may occur in some nodules which may resolve spontaneously over 4-6 weeks. [2,3]
Nonspecific symptoms Some patients may show nonspecific symptoms such as fever, diarrhea or abdominal cramping. [1,3]
At risk population The virus transmit from direct contact when an individual in contact with an infected animal. So, the disease is more common among milkers, farm workers caring for dairy cattle, stockyard workers, butchers, and veterinarians. [2,3]
References
  1. CARGNELUTTI JF, FLORES MM, TEIXEIRA FR, WEIBLEN R, FLORES EF. An outbreak of pseudocowpox in fattening calves in southern Brazil. J Vet Diagn Invest [online] 2012 Mar, 24(2):437-41 [viewed 03 August 2014] Available from: doi:10.1177/1040638711435408
  2. OEM JK, LEE EY, LEE KK, KIM SH, LEE MH, HYUN BH. Bovine papular stomatitis virus (BPSV) infections in Korean native cattle. J Vet Med Sci [online] 2013, 75(5):675-8 [viewed 03 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/23292127
  3. DE SANT'ANA FJ, RABELO RE, VULCANI VA, CARGNELUTTI JF, FLORES EF. Bovine papular stomatitis affecting dairy cows and milkers in midwestern Brazil. J Vet Diagn Invest [online] 2012 Mar, 24(2):442-5 [viewed 03 August 2014] Available from: doi:10.1177/1040638711434799

Examination

Fact Explanation
Skin lesion The lesion begins as an erythematous maculopapular rash, commonly on fingers and occasionally over the face. These are 0.5-1.5 cm in diameter, firm, movable and dome-shaped. They are red or purplish red in color and may show a central ulceration which happens to be a grayish crust. The lesions may be tender, solitary or multiple, and may show secondary bacterial infections. [1,2,3]
Lymphadenopathy Rarely localized tender lymph node enlargement can be observed. [2,3]
References
  1. CARGNELUTTI JF, FLORES MM, TEIXEIRA FR, WEIBLEN R, FLORES EF. An outbreak of pseudocowpox in fattening calves in southern Brazil. J Vet Diagn Invest [online] 2012 Mar, 24(2):437-41 [viewed 03 August 2014] Available from: doi:10.1177/1040638711435408
  2. DE SANT'ANA FJ, RABELO RE, VULCANI VA, CARGNELUTTI JF, FLORES EF. Bovine papular stomatitis affecting dairy cows and milkers in midwestern Brazil. J Vet Diagn Invest [online] 2012 Mar, 24(2):442-5 [viewed 03 August 2014] Available from: doi:10.1177/1040638711434799
  3. OEM JK, LEE EY, LEE KK, KIM SH, LEE MH, HYUN BH. Bovine papular stomatitis virus (BPSV) infections in Korean native cattle. J Vet Med Sci [online] 2013, 75(5):675-8 [viewed 03 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/23292127

Differential Diagnoses

Fact Explanation
Cow pox infection Cowpox is caused by the cowpox or cowpox virus, a member of the orthopoxvirus family. The virus is zoonotic, or transferable from animal to human. It is acquired by direct contact with an infected animal (cat in most of cases) to a human during a scratch or bite . Cowpox infection is very rare nowadays. Most cases have been reported in Great Britain and other European countries. In cowpox disease, small number of skin lesions appears on the hands and face. Initially the site of infection appears as an inflamed flat red lesion (macule). Then, the inflamed lesion becomes raised (papular) and develops into a blister-like sore (vesicle). [1]
Herpes Simplex Herpes simplex is a common viral infection by Herpes Simplex Virus (HSV) that presents with localised blistering. It affects most people on one or more occasions during their lives. is a viral disease from the herpesviridae family caused by both HSV-1 and HSV-2 types. HSV infection causes several distinct medical disorders. Common infection of the skin or mucosa may affect the face and mouth (orofacial herpes), genitalia (genital herpes), or hands (herpetic whitlow). More serious disorders occur when the virus infects and damages the eye (herpes keratitis), or invades the central nervous system, damaging the brain (herpes encephalitis). [2]
Orf Orf is an infection caused by a parapox virus called by the same name. It is a common among sheep and goats. Direct contact with an infected animal or contaminated fomites results in transmission of the virus to human body. Therefore, Orf is frequently seen in farmers and meat handlers. Orf lesions are generally solitary or few in number. Though the classical site is the dorsum of the index finger, it can be seen on other fingers, hands, forearms or on face. [3]
References
  1. STRENGER V, MüLLER M, RICHTER S, REVILLA-FERNANDEZ S, NITSCHE A, KLEE SR, ELLERBROK H, ZENZ W. A 17-year-old girl with a black eschar. Cowpox virus infection. Clin Infect Dis [online] 2009 Jan 1, 48(1):91-2, 133-4 [viewed 03 August 2014] Available from: doi:10.1086/595004
  2. MIRANDA CA, LIMA EG, DE LIMA DB, COBUCCI RN, CORNETTA MDA C, FERNANDES TA, DE AZEVEDO PR, DE AZEVEDO JC, DE ARAúJO JM, FERNANDES JV. Genital infection with herpes simplex virus types 1 and 2 in women from natal, Brazil. ISRN Obstet Gynecol [online] 2014:323657 [viewed 03 August 2014] Available from: doi:10.1155/2014/323657
  3. KITCHEN M, MüLLER H, ZOBL A, WINDISCH A, ROMANI N, HUEMER H. ORF virus infection in a hunter in Western Austria, presumably transmitted by game. Acta Derm Venereol [online] 2014 Mar, 94(2):212-4 [viewed 02 August 2014] Available from: doi:10.2340/00015555-1643

Investigations - for Diagnosis

Fact Explanation
Viral culture Viral cultures take time. Even though it can not differentiate between orf and milker's nodule. [1,2]
Polymerase chain reaction (PCR) PCR may be performed on biopsy material or cell culture. This is diagnostic of pseudocowpox virus. [2,3]
Electron microscopy Electron microscopic evaluation of crust or biopsy material may reveal viral particles. Still the definitive diagnosis of pseudocowpox virus can not be made. [1,2,3]
Skin biopsy for histology A shave biopsy is performed for hematoxylin and eosin tissue histology. The characteristic pathological features are epidermal hyperplasia, marked swelling of the dermis, intra epidermal and subepidermal blistering, and a dense mixed inflammatory infiltrate. [1,2,3]
References
  1. DE SANT'ANA FJ, RABELO RE, VULCANI VA, CARGNELUTTI JF, FLORES EF. Bovine papular stomatitis affecting dairy cows and milkers in midwestern Brazil. J Vet Diagn Invest [online] 2012 Mar, 24(2):442-5 [viewed 03 August 2014] Available from: doi:10.1177/1040638711434799
  2. CARGNELUTTI JF, FLORES MM, TEIXEIRA FR, WEIBLEN R, FLORES EF. An outbreak of pseudocowpox in fattening calves in southern Brazil. J Vet Diagn Invest [online] 2012 Mar, 24(2):437-41 [viewed 03 August 2014] Available from: doi:10.1177/1040638711435408
  3. OEM JK, LEE EY, LEE KK, KIM SH, LEE MH, HYUN BH. Bovine papular stomatitis virus (BPSV) infections in Korean native cattle. J Vet Med Sci [online] 2013, 75(5):675-8 [viewed 03 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/23292127

Management - General Measures

Fact Explanation
Antiviral treatment Antiviral medications are not routinely indicated. [1]
Antibiotics Topical or systemic antibiotics are only used in case of secondary bacterial infection. [2,3]
Surgical options Superficial shave excision has been found to be effective as it reduces the viral load by a considerably high number and hence, speed up the healing process. Curettage and cautery can be started in conjunction with shave excision. [1,2,3]
Prevention Animals who are infected with the virus should be detected early and isolated. The infections can be identified when animals with typical lesions of circinate or horseshoe-shaped crusted erosions around moist surfaces of the mouth and nose or papules and erosions around the teats. Gloves should be worn if milking. [1,2,3]
References
  1. CARGNELUTTI JF, FLORES MM, TEIXEIRA FR, WEIBLEN R, FLORES EF. An outbreak of pseudocowpox in fattening calves in southern Brazil. J Vet Diagn Invest [online] 2012 Mar, 24(2):437-41 [viewed 03 August 2014] Available from: doi:10.1177/1040638711435408
  2. DE SANT'ANA FJ, RABELO RE, VULCANI VA, CARGNELUTTI JF, FLORES EF. Bovine papular stomatitis affecting dairy cows and milkers in midwestern Brazil. J Vet Diagn Invest [online] 2012 Mar, 24(2):442-5 [viewed 03 August 2014] Available from: doi:10.1177/1040638711434799
  3. OEM JK, LEE EY, LEE KK, KIM SH, LEE MH, HYUN BH. Bovine papular stomatitis virus (BPSV) infections in Korean native cattle. J Vet Med Sci [online] 2013, 75(5):675-8 [viewed 03 August 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/23292127