Laxmisha C, Thappa DM, Pandian S, Jayanthi S

Bioline International

Indian J Dermatol Venereol Leprol November-December 2003 Vol 69 Issue 6425CMYK425QuizA 30-year-old milkmaid had asymptomatic 1.5-2.0 cmscrusted nodules over her left forearm, right index(Figure 1) and right middle finger of two and an halfweeks duration. She gave a history of similar lesionsoccurring over the teats of her cows three weeks back.The lesions had initially started as papules, whichturned vesicular in four days time and were followedby crusting a week later. There was no evidence of feveror lymphadenopathy.Histopathological examination of the skin nodule (overthe finger) showed hyperkeratosis, markedparakeratosis and acanthosis. There was vacuolizationof cells in the upper third of the stratum malpighi andthe dermis showed vasodilatation and chronicinflammation (Figure 2). Higher magnificationdemonstrated eosinophilic inclusion bodies in thecytoplasm of vacuolated epidermal cells (Figure 3).Figure 1:Dorsa of the finger showing an umbilicated noduleFigure 2:Photomicrograph of skin biopsy specimen showingmarked parakeratosis and acanthosis.  There isvacuolization of cells in the upper third of the stratummalpighi and the dermis shows vasodilatation andchronic inflammation (Hematoxylin & Eosin x 100)Figure 3:Higher magnification photomicrograph demonstratingeosinophilic inc lusion bodies in the cytoplasm ofvacuolated epidermal cells (Hematoxylin & Eosin x 200)Asymptomatic nodules over forearm and handWHAT IS YOUR DIAGNOSIS?How to cite this article: Laxmisha C, Thappa DM, Pandian S, Jayanthi S. Asymptomatic nodules over forearm and hand  Indian J DermatolVenereol Leprol 2003;69:425-6.Received: August, 2003. Accepted: September, 2003. Source of Support: Nil.Indian J Dermatol Venereol Leprol November-December 2003 Vol 69 Issue 6 426426 CMYKDiagnosis: Milker’s nodulesDISCUSSIONMilker’s nodule, also known as paravaccinia orpseudocowpox, is a worldwide occupational diseaseof milker’s or veterinarians, caused by the paravacciniavirus.1 It is most commonly directly transmitted fromthe udders of infected cows.2 Most cases are sporadic,but small epidemics have been reported. The typicalcase consists of a single asymptomatic or slightlypainful, one cm erythematous nodule on a finger. Thereare usually no more than four lesions, and they aregenerally confined to the hands and forearm. Theincubation period is 4-7 days, but may be as long astwo weeks. They usually heal spontaneously in 4-6weeks without scar formation. Lavell and Phillips1 havedescribed six clinical stages, each lasting about a week.They include macular, papular, target like, nodular,granulomatous / papillomatous and regressive stage.The diagnosis in our case was based on history, clinicalexamination and biopsy.Histology shows the presence of vacuolatedkeratinocytes with intracytoplasmic inclusions (3-5microns in size) in the first two stages, followed bymultilocular vesicles with associated lymphohistiocyticdermal infiltrate and plasma cells during the third stage.Acanthosis and papillomatosis are very prominent inthe 5th and 6th stages. 3 Atypical presentations withoutmarked viral changes may potentially cause diagnosticconfusion, which can be diagnosed by electronmicroscopy or tissue culture.4 Other diagnosticmodalities include complement fixation test andfluorescent antibody technique.3Although both Orf and Milker’s nodule are clinicallyidentical, it is the source of infection: sheep and goatsversus cows, which distinguishes the two.3 Because ofthe clinical similarity of the two diseases, the collectiveterm “Farmyard-pox” has been used.4 In cow pox, thedomestic cat is the source of infection and the lesionsare usually painful associated with lymphadenopathy.Histologic evaluation in human cases has not revealeddiagnostic cytoplasmic inclusions; but has revealedvacuolar degeneration of the epidermis.2 Anthrax is alsopainless and develops an eschar by day 6.2 The otherconditions- atypical mycobacterial infection, primaryinoculation tuberculosis, sporotrichosis, herpeticwhitlow, etc can be differentiated based on histologyand culture of the lesions.Since the disease is self limiting, only symptomatictreatment is generally indicated. One episode inhumans usually induces lasting immunity.1Contributed by:Chandrashekar Laxmisha, Devinder MohanThappa, Sathesh Pandian, S Jayanthi*Depar tment of Dermatology and STD, and *Pathology, JawaharlalInstitute of Postgraduate Medical Education and Research(JIPMER), Pondicherr y - 605006, India.Address for correspondence: Dr. Devinder Mohan Thappa,Department of Dermatology and STD, JIPMER, P ondicherr y -605006, India.E-mail- dmthappa@vsnl.netREFERENCES1. Lowy DR. Milker’s nodule. In: Freedberg IM, Eisen AZ, WolffK, Austen KF, Goldsmith LA, Katz SI, et al. editors. Fitzpatrick’sDermatology in General Medicine. 5th ed. New York: McGraw-Hill Publications; 1999. p. 2482-3.2. Odom RB, James WD, Berger TG. Andrew’s Diseases of theSkin. 9th ed. Philadelphia: WB Saunders Company; 2000. p.473-525.3. Diven DG. An overview of poxviruses. J Am Acad Dermatol2001;44:1-16.4. Groves RW, Wilson-Jones E, MacDonald DM. Human Or f andMilker ’s nodule: a clinicopathological study. J Am AcadDermatol 1991;25:706-11.Quiz

Asymptomatic nodules over forearm and hand

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