Unknown: Pink pigtail in a skin Unknown: Pink pigtail in a skin biopsy: What is your diagnosis? biopsy: What is your diagnosis?

Erica F Reinig BS, Dan Albertson MD, Deba Erica F Reinig BS, Dan Albertson MD, Deba P Sarma MDP Sarma MDDermatology Online Journal 17 (1): 12 Dermatology Online Journal 17 (1): 12 (2011)(2011)

A 63-year-old man undergoing treatment A 63-year-old man undergoing treatment for immunoproliferative disease was for immunoproliferative disease was suspected of having a pruritic drug suspected of having a pruritic drug eruption. Subsequent skin biopsy eruption. Subsequent skin biopsy revealed three intracorneal pink, revealed three intracorneal pink, refractile pigtail-like structures, one refractile pigtail-like structures, one attached to the stratum corneum and the attached to the stratum corneum and the other two free in a cavity (Figures 1 and other two free in a cavity (Figures 1 and 2).2).

What is the diagnosis?What is the diagnosis?

Figure 1

Figure 2

AbstractAbstract Sarcoptes scabieiSarcoptes scabiei is an obligate ectoparasite, which is an obligate ectoparasite, which

burrows into the stratum granulosum of the epidermis burrows into the stratum granulosum of the epidermis and lays its eggs. The resultant host inflammatory and lays its eggs. The resultant host inflammatory response leads to intensely pruritic papules. CASE response leads to intensely pruritic papules. CASE SYNOPSIS: A 63-year-old man undergoing treatment SYNOPSIS: A 63-year-old man undergoing treatment for immunoproliferative disease was suspected of for immunoproliferative disease was suspected of having a pruritic drug eruption. Subsequent skin having a pruritic drug eruption. Subsequent skin biopsy revealed an intracorneal burrow containing biopsy revealed an intracorneal burrow containing three pink, refractile pigtail-like structures, believed to three pink, refractile pigtail-like structures, believed to be empty eggshells of be empty eggshells of S. scabieiS. scabiei. CONCLUSION: . CONCLUSION: Traditionally, the presence of adult mites or eggs in Traditionally, the presence of adult mites or eggs in skin scrapings or a skin biopsy is required for a skin scrapings or a skin biopsy is required for a definitive diagnosis of scabies. However, our case and definitive diagnosis of scabies. However, our case and similar cases suggest that the diagnosis of scabies can similar cases suggest that the diagnosis of scabies can also be made on the basis of pink pigtail-like also be made on the basis of pink pigtail-like structures, remnants of eggshells, within the structures, remnants of eggshells, within the intracorneal burrow. intracorneal burrow.

Answer: Answer: ScabiesScabies

DiscussionDiscussion Sarcoptes scabieiSarcoptes scabiei is an eight-legged, tan-brown obligate is an eight-legged, tan-brown obligate

ectoparasitic arachnid that is transmitted by direct and ectoparasitic arachnid that is transmitted by direct and prolonged person-to-person contact. As a result of this prolonged person-to-person contact. As a result of this means of transmission, scabies is largely believed to be a means of transmission, scabies is largely believed to be a disease of overcrowding and close-proximity and not an disease of overcrowding and close-proximity and not an indication of poor hygiene [indication of poor hygiene [1]. Typically measuring 0.3 to ]. Typically measuring 0.3 to 0.5 mm, the female mite burrows into the stratum 0.5 mm, the female mite burrows into the stratum granulosum of the epidermis. From there, it continues to granulosum of the epidermis. From there, it continues to move and lay eggs along the way, eventually dying within move and lay eggs along the way, eventually dying within two to three months.two to three months.

Clinically, affected individuals present with symptoms two Clinically, affected individuals present with symptoms two to four weeks following the initial infestation; they to four weeks following the initial infestation; they primarily complain of intense itching that worsens at primarily complain of intense itching that worsens at night. Examination of the skin demonstrates the presence night. Examination of the skin demonstrates the presence of small, erythematous papules, which may show thin of small, erythematous papules, which may show thin burrow lines measuring several millimeters in length. The burrow lines measuring several millimeters in length. The pruritic papules in patients with scabies are classically pruritic papules in patients with scabies are classically located in the webs of the fingers, the flexor aspects of located in the webs of the fingers, the flexor aspects of the wrists, the extensor surfaces of the elbows, the the wrists, the extensor surfaces of the elbows, the periumbilical skin, buttocks, ankles, and genital areas. periumbilical skin, buttocks, ankles, and genital areas. The back and head are spared in most cases. On the The back and head are spared in most cases. On the more severe end of the clinical spectrum, crusted scabies more severe end of the clinical spectrum, crusted scabies is a debilitating disease characterized by very large is a debilitating disease characterized by very large numbers of mites that cause the development of numbers of mites that cause the development of hyperkeratotic crusts that may affect the neck, scalp, hyperkeratotic crusts that may affect the neck, scalp, face, eyelids, and subungual sites. face, eyelids, and subungual sites.

Whereas crusted scabies is often associated with chronic Whereas crusted scabies is often associated with chronic infections, debilitation, and immunosuppression, cases in infections, debilitation, and immunosuppression, cases in apparently immunocompetent hosts have been described [apparently immunocompetent hosts have been described [2]. As a result of frequent scratching that produces open ]. As a result of frequent scratching that produces open excoriations, secondary infections, especially group A excoriations, secondary infections, especially group A streptococci and streptococci and Staphylococcus aureusStaphylococcus aureus can result in can result in cellulitis and more invasive bacterial infections. Scabies cellulitis and more invasive bacterial infections. Scabies infestations are primarily treated with topical agents, such infestations are primarily treated with topical agents, such as permethrin cream (5%), or oral antihelmintics, such as as permethrin cream (5%), or oral antihelmintics, such as ivermectin (200 mcg per kg in one dose, which may be ivermectin (200 mcg per kg in one dose, which may be repeated in 2 weeks). In individuals with more severe repeated in 2 weeks). In individuals with more severe disease, extended treatment may be necessary.disease, extended treatment may be necessary.

Whereas a skin scraping is the more traditional means of Whereas a skin scraping is the more traditional means of detection, occasionally when the diagnosis of scabies is detection, occasionally when the diagnosis of scabies is missed clinically, evidence of a scabies infection can also missed clinically, evidence of a scabies infection can also be observed on skin biopsy. In these cases, be observed on skin biopsy. In these cases, histopathological findings may include burrows in the histopathological findings may include burrows in the stratum corneum, parakeratotic mounds, inflammatory cell stratum corneum, parakeratotic mounds, inflammatory cell infiltrates (lymphocytes, histiocytes, and eosinophils), adult infiltrates (lymphocytes, histiocytes, and eosinophils), adult mites, and embryonated eggs in various stages of mites, and embryonated eggs in various stages of development [development [3]. Traditionally, a definitive diagnosis of an ]. Traditionally, a definitive diagnosis of an infection by infection by S. scabieiS. scabiei has been reserved for cases in which has been reserved for cases in which skin scraping or biopsy demonstrates an adult mite or an skin scraping or biopsy demonstrates an adult mite or an egg. Whereas these findings are very specific for scabies, egg. Whereas these findings are very specific for scabies, sensitivity is less than 50 percent because only a few mites sensitivity is less than 50 percent because only a few mites or eggs may be present in the skin at any time during or eggs may be present in the skin at any time during infection. Poor sensitivity may lead to an uncertain infection. Poor sensitivity may lead to an uncertain diagnosis, a delay in treatment, and possibly an increased diagnosis, a delay in treatment, and possibly an increased risk of secondary infection. More recent advances in the risk of secondary infection. More recent advances in the development of an development of an S. scabieiS. scabiei immunodiagnostic assay are immunodiagnostic assay are underway and may yield a more sensitive means of underway and may yield a more sensitive means of diagnosing individuals, thus leading to selective treatment diagnosing individuals, thus leading to selective treatment of individuals in endemic areas [of individuals in endemic areas [1]. ].

In our case, no mites or eggs were visible in the biopsy In our case, no mites or eggs were visible in the biopsy specimen. However, there were distinctly visible pink specimen. However, there were distinctly visible pink pigtail-like structures within the intracorneal burrow. In pigtail-like structures within the intracorneal burrow. In serial sections the mite may be seen at various stages of serial sections the mite may be seen at various stages of development demonstrating that these pigtail structures development demonstrating that these pigtail structures are formed as the scabies egg hatches and leaves behind are formed as the scabies egg hatches and leaves behind an empty shell [an empty shell [4]. In agreement with the observation of ]. In agreement with the observation of other authors [other authors [4], our case suggests that it is possible to ], our case suggests that it is possible to make a diagnosis of scabies without a visible egg or mite make a diagnosis of scabies without a visible egg or mite when these pink pigtail structures, indicative of empty when these pink pigtail structures, indicative of empty scabies eggshells, are observed. In such cases, a prompt scabies eggshells, are observed. In such cases, a prompt diagnosis will allow timely treatment of the infection.diagnosis will allow timely treatment of the infection.

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Scabies, a Global Disease in Human and Animal Scabies, a Global Disease in Human and Animal Populations.” Clinical Microbiology Review, vol. 20, pp. Populations.” Clinical Microbiology Review, vol. 20, pp. 268-279, 2007. [268-279, 2007. [PubMed]]

2. H.B. Gladstone and G.L. Darmstadt. “Crusted Scabies in 2. H.B. Gladstone and G.L. Darmstadt. “Crusted Scabies in an Immunocompetent Child: Treatment with Ivermectin.” an Immunocompetent Child: Treatment with Ivermectin.” Pediatric Dermatology, vol. 2, pp. 144-148, 2000. [Pediatric Dermatology, vol. 2, pp. 144-148, 2000. [PubMed]]

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4. A.K. Kristjansson, M.K. Smith, J.W. Gould, and A.C. 4. A.K. Kristjansson, M.K. Smith, J.W. Gould, and A.C. Gilliam. “Pink pigtails are a clue for the diagnosis of Gilliam. “Pink pigtails are a clue for the diagnosis of scabies.” Journal of the American Academy of scabies.” Journal of the American Academy of Dermatology, vol. 57, no. 1, pp. 174-175, 2007. [PubMed]Dermatology, vol. 57, no. 1, pp. 174-175, 2007. [PubMed]

REF:REF: Reinig EF, Albertson D, Reinig EF, Albertson D, Sarma DPSarma DP.(2011) Unknown: Pink pigtails .(2011) Unknown: Pink pigtails

in a skin biopsy: What is your diagnosis? Dermatology Online in a skin biopsy: What is your diagnosis? Dermatology Online Journal 17(1): 12,[Pubmed-indexed in MEDLINE].Journal 17(1): 12,[Pubmed-indexed in MEDLINE].