An unusual finger injury
Transcription
An unusual finger injury
BMJ 2016;353:i2680 doi: 10.1136/bmj.i2680 (Published 25 May 2016) Page 1 of 4 Endgames ENDGAMES CASE REVIEW An unusual finger injury 1 2 1 David A Pettitt doctoral research fellow and clinical fellow , Ashwin Pai clinical fellow , Emma 1 Bradbury general practitioner , Suresh Anandan associate specialist in plastic and reconstructive 1 1 surgery , Mahendra Kulkarni consultant plastic and reconstructive surgeon Department of Plastic and Reconstructive Surgery, Wexham Park Hospital, Slough SL2 4L, UK; 2Department of Paediatrics, University of Oxford, Oxford, UK 1 A 39 year old female farmer with no medical history presented to the emergency department with a painless swelling over her right index finger. The problem started two weeks earlier after she had been bitten by a lamb. After the injury the finger appeared “bruised.” This bruising continued and a swelling gradually developed. She reported no pain, changes in sensation, or reduced range of movement. On clinical examination she was afebrile and haemodynamically stable. Her right index finger exhibited a full range of movement and was neurovascularly intact. The finger was not tender on direct palpation and it seemed to be the same temperature as her other fingers. The finger had a laceration on the radial aspect proximal to the nail fold, with a demarcated and raised area of reddish-blue discoloration measuring about 2 cm × 1.5 cm (fig 1). There was no palpable lymphadenopathy within the axilla. Fig 1 Injured right index finger Questions 1.What are the differential diagnoses? 2.What is the most likely diagnosis? 3.What investigations might be ordered? 4.How is this condition managed? Answers 1. What are the differential diagnoses? Short answer Bruising (eg post-trauma), paronychia, herpetic whitlow, orf virus infection, Milker’s nodule, pyogenic granuloma, keratoacanthoma, and osteomyelitis. Discussion Bruising is a common soft tissue injury (fig 2). It is often secondary to trauma and is characterised by a bluish or purple coloured patch as a result of underlying capillary damage. Bruising is typically painful initially and usually resolves within a few weeks, fading to a greenish-yellow colour before the skin finally returns to normal. Fig 2 Bruising to the finger. Credit: Dr P Marazzi/Science Photo Library.SPL In paronychia (fig 3) the infection generally starts in the paronychium at the side of the nail, with local redness, swelling, and pain. The lesion is tender on palpation and may be warmer than the surrounding tissue. There is usually a pre-existing injury or some predisposing factor. It can be acute or chronic and of bacterial or fungal origin.1 Correspondence to: D A Pettitt [email protected] For personal use only: See rights and reprints http://www.bmj.com/permissions Subscribe: http://www.bmj.com/subscribe BMJ 2016;353:i2680 doi: 10.1136/bmj.i2680 (Published 25 May 2016) Page 2 of 4 ENDGAMES Fig 6 Pyogenic granuloma on the finger . Dr P Marazzi/Science Photo Library.SPL Fig 3 Paronychia infection of the finger. Credit: Dr P Marazzi/Science Photo Library.SPL Herpetic whitlow is a lesion or lesions on a finger or thumb caused by the herpes simplex virus (fig 4). It is a painful infection that typically affects fingers or thumbs. The vesicular lesions are usually small, localised, and grouped together. It is most commonly contracted by dental workers and medical workers exposed to oral secretions.2 Keratoacanthoma is characteristically dome shaped, symmetrical, surrounded by a smooth wall of inflamed skin, and capped with keratin scales and debris (fig 7). It grows rapidly, reaching a large size within days or weeks. If left untreated, it almost always undergoes necrosis, sloughing, and healing with scarring over a few months. It is commonly found on sun exposed skin, often the face, forearms and hands.4 Fig 7 Keratoacanthoma on the back of the hand. Dr P Marazzi/Science Photo Library.SPL Fig 4 Herpes infection causing blisters on fingers (herpetic whitlow). Credit: Dr P Marazzi/Science Photo Library.SPL Orf virus infection is a zoonotic disease, which humans can contract through direct contact with infected animals (usually sheep and goats) or with fomites carrying the orf virus. It causes a purulent appearing papule locally (fig 5) and generally no systemic symptoms. It is caused by a parapox virus.1 2 Osteomyelitis is inflammation of the bone (fig 8), usually caused by infection with Staphylococcus aureus. It can be acute or chronic, and both patterns have similar symptoms, including fever and nausea and localised symptoms around the affected bone, such as tenderness, warmth, erythema, and reduced range of motion. A diagnosis is usually made using radiography or magnetic resonance imaging.5 Fig 8 An infected ischaemic toe. Dr P Marazzi/Science Photo Library.SPL 2. Fig 5 Orf disease lesion on the finger. Credit: Dr P Marazzi/Science Photo Library.SPL Milker’s nodule is a cutaneous condition most commonly transmitted from the udders of infected cows. Also known as milkmaid blisters, it is caused by the paravaccinia virus. Disease in humans is similar to orf infection but can be differentiated with a thorough history.3 Pyogenic granuloma is a small, benign vascular lesion (fig 6) that occurs on both mucosa and skin (often on the hands, arms, or face). It is caused by irritation, physical trauma, or hormonal factors and it appears as an overgrowth.2 4 These granulomas are often found at the site of recent injury and bleed easily on contact.2 For personal use only: See rights and reprints http://www.bmj.com/permissions What is the most likely diagnosis? Short answer Orf virus infection is the most likely diagnosis because of the history of an animal bite followed by the appearance of a painless blue-black maculopapular lesion that does not affect range of movement. Discussion This patient had an orf virus infection. Orf (also known as Ecthyma contagiosum) infection is a viral zoonotic infection caused by a dermotropic double stranded DNA parapoxvirus. It typically presents three to four weeks after an animal bite as a painless swelling, which is blue-black in colour. There is usually minimal cellulitis and no associated lymphadenopathy. Orf infection is most common in people who are closely involved with animal handling,6 such as farmers (particularly Subscribe: http://www.bmj.com/subscribe BMJ 2016;353:i2680 doi: 10.1136/bmj.i2680 (Published 25 May 2016) Page 3 of 4 ENDGAMES those handling sheep and goats),veterinary professionals, and butchers.7 Orf progresses through six distinct stages8: • Stage 1. Maculopapular stage: the lesion appears as an erythematous macule or papule • Stage 2. Target stage: an outer halo appears around the central red area, similar to a target sign • Stage 3. Acute stage: purulent discharge may be seen from the nodule • Stage 4. Regenerative stage: the nodule becomes dry • Stage 5. Papillomatous stage: the nodule becomes a papilloma-like lesion • Stage 6. Regression stage: the papilloma starts to crust over and ultimately resolves. Orf infection is often misdiagnosed as a bacterial infection and ultimately mistreated with antimicrobial therapy, which can lead to complications such as gastrointestinal upset or hypersensitivity reactions.9-11 3. What investigations might be ordered? Short answer Orf infection is usually diagnosed clinically, but a finger radiograph and wound swab might rule out differential diagnoses. Diagnosis can be confirmed by electron microscopy or DNA polymerase chain reaction. Discussion The diagnosis of orf infection is typically made on clinical grounds but the following can help rule out differential diagnoses: • Finger radiography to identify any signs of osteomyelitis or bony injury • Wound swabs are typically negative in orf infection unless there is a secondary bacterial infection. Blood tests are not required for orf infection. Orf infection can formally be diagnosed by electron microscopy or DNA polymerase chain reaction. Electron microscopy shows ovoid cross hatched virions, but it cannot distinguish orf virus from other parapoxviruses, whereas PCR can definitively identify a parapoxvirus as orf virus.12 13 4. How is this condition managed? Short answer Basic wound care, advice about hand hygiene, and discussion with plastic and reconstructive surgery specialists if there are concerns or complications. Discussion Both general and hospital practitioners are advised that orf infection is a benign, self limiting condition, and that in the absence of complications specific antimicrobial therapy or specialist management is not needed. Spontaneous healing usually occurs within a few weeks of infection. Although several studies on the use of topical imiquimod cream have had favourable results,14 conservative management, including basic wound care and advice on hand hygiene (regular For personal use only: See rights and reprints http://www.bmj.com/permissions cleansing with soap and water or saline solution), is recommended. With conservative management, the infection normally subsides within three to four weeks, with no scarring or loss of function. In rare cases, where the lesions are extremely large, surgical excision and skin grafting may be needed.11 15 If secondary bacterial infection occurs there may be tenderness and warmth on palpation, cellulitic skin changes, increasing pain, and systemic features such as fever and malaise in more severe cases. In such cases oral antibiotics can be prescribed. Refer patients who present with surrounding cellulitis and spreading lymphangitis to their nearest on-call plastic and reconstructive surgery unit, where they will usually be admitted for hand elevation and a short course of intravenous antibiotics. If there are any queries or concerns about complications, clinicians can contact their nearest on-call plastic and reconstructive surgery unit. Clinicians can advise patients at risk of orf infection to consider taking preventive measures, such as wearing thick, non-permeable rubber gloves when handling farm animals and having the animals immunised with a live orf vaccine.8 16 Patient outcome This patient was discharged home after being reviewed by a senior plastic surgeon and being given a clinical diagnosis of orf infection. At review four weeks later in the outpatient plastic surgery clinic she had made a full recovery, with a full range of movement and no residual discoloration. Competing interests: We have read and understood BMJ policy on declaration of interests and declare the following interests: none. Provenance and peer review: Commissioned; not externally peer reviewed. Patient consent obtained. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Bodilsen J, Leth S. [Orf parapoxvirus can infect humans after relevant exposure]. Ugeskr Laeger 2013;175:1121-2.pmid:23651755. Inceoğlu F. Orf (ecthyma contagiosum): an occasional diagnostic challenge. Plast Reconstr Surg 2000;106:733-4. doi:10.1097/00006534-200009010-00038 pmid:10987487. Groves RW, Wilson-Jones E, MacDonald DM. Human orf and milkers’ nodule: a clinicopathologic study. J Am Acad Dermatol 1991;25:706-11. doi:10.1016/0190-9622( 91)70257-3 pmid:1838751. Mourtada I, Le Tourneur M, Chevrant-Breton J, Le Gall F. [Human orf and erythema multiforme]. Ann Dermatol Venereol 2000;127:397-9.pmid:10844261. Carek PJ, Dickerson LM, Sack JL. Diagnosis and management of osteomyelitis. Am Fam Physician 2001;63:2413-20.pmid:11430456. Buchan J. Characteristics of orf in a farming community in mid-Wales. BMJ 1996;313:203-4. doi:10.1136/bmj.313.7051.203 pmid:8696196. Paiba GA, Thomas DR, Morgan KL, et al. Orf (contagious pustular dermatitis) in farmworkers: prevalence and risk factors in three areas of England. Vet Rec 1999;145:7-11. doi:10.1136/vr.145.1.7 pmid:10452390. Centers for Disease Control and Prevention (CDC). Orf virus infection in humans--New York, Illinois, California, and Tennessee, 2004-2005. MMWR Morb Mortal Wkly Rep 2006;55:65-8.pmid:16437055. Torfason EG, Gunadóttir S. Polymerase chain reaction for laboratory diagnosis of orf virus infections. J Clin Virol 2002;24:79-84. doi:10.1016/S1386-6532(01)00232-3 pmid: 11744431. Gallina L, Dal Pozzo F, Mc Innes CJ, et al. A real time PCR assay for the detection and quantification of orf virus. J Virol Methods 2006;134:140-5. doi:10.1016/j.jviromet.2005. 12.014 pmid:16430972. Degraeve C, De Coninck A, Senneseael J, Roseeuw D. Recurrent contagious ecthyma (Orf) in an immunocompromised host successfully treated with cryotherapy. Dermatology 1999;198:162-3. doi:10.1159/000018095 pmid:10325465. Sanchez RL, Hebert A, Lucia H, Swedo J. Orf. A case report with histologic, electron microscopic, and immunoperoxidase studies. Arch Pathol Lab Med 1985;109:166-70.pmid: 3883947. Torfason EG, Gunadóttir S. Polymerase chain reaction for laboratory diagnosis of orf virus infections. J Clin Virol 2002;24:79-84. doi:10.1016/S1386-6532(01)00232-3 pmid: 11744431. Erbağci Z, Erbağci I, Almila Tuncel A. Rapid improvement of human orf (ecthyma contagiosum) with topical imiquimod cream: report of four complicated cases. J Dermatolog Treat 2005;16:353-6. doi:10.1080/09546630500375734 pmid:16428161. Shelley WB, Shelley ED. Surgical treatment of farmyard pox. Orf, milker’s nodules, bovine papular stomatitis pox. Cutis 1983;31:191-2.pmid:6299651. Subscribe: http://www.bmj.com/subscribe BMJ 2016;353:i2680 doi: 10.1136/bmj.i2680 (Published 25 May 2016) Page 4 of 4 ENDGAMES 16 Centers for Disease Control and Prevention. Human orf mimicking cutaneous anthrax—California. MMWR 1973;22:108. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/ permissions For personal use only: See rights and reprints http://www.bmj.com/permissions Subscribe: http://www.bmj.com/subscribe