The name rickettsialpox is derived from the causative organism Rickettsia akari and the similarity of the cutaneous lesions to chickenpox [1]. The disease can affect all ages and has an equal incidence in men and women [1]. Cases of rickettsialpox, infected mites, and R.akari reservoirs have been reported from countries like the United States, Turkey, Croatia, and Ukraine [2] [3] [4] [5] [6].

The rickettsia proliferates at the site of the mite bite with symptoms appearing up to two weeks later. Initially, a tiny, non-tender papule or vesicle is seen at the site of the bite. It soon forms an ulcer with eschar which heals with a scar. This may or may not be associated with regional lymphadenopathy [7]. A week later constitutional symptoms like fever, chills, headaches, myalgias, photophobia, diaphoresis and a generalized maculopapular rash with papulovesicular lesions sparing the palms and soles appears. The pruritic lesions can be seen on the trunk, limbs, face, lingual, buccal and pharyngeal mucosa. They last for approximately a week and heal without scarring. Rarely there may be associated neurological symptoms like photophobia, vertigo, retro-orbital pain, neck stiffness [3]. Cases of hepatitis have also been reported [8]. Rickettsialpox is a self-limiting disease and not associated with mortality. However, severe hemorrhage in a patient with rickettsia and variations in clinical presentations amongst patients in different parts of the world is known to exist [9].

• Fever

  […] spotted fever, boutonneuse fever, louse-borne typhus fever, and murine typhus. [ncbi.nlm.nih.gov]

  "NEW FEVER TRACED TO MITE ON MICE; U.S. [en.wikipedia.org]

• Chills

  (with rigor) R50.9 ICD-10-CM Diagnosis Code R50.9 Fever, unspecified 2016 2017 2018 2019 Billable/Specific Code Applicable To Fever NOS Fever of unknown origin [FUO] Fever with chills Fever with rigors Hyperpyrexia NOS Persistent fever Pyrexia NOS Kew [icd10data.com]

  Rickettsialpox causes rash, fever, chills, heavy sweating, headache, eye pain (especially when exposed to light), weakness, and achy muscles. [encyclopedia.com]

  Fever, chills, swollen lymph nodes, rash, muscle pain, headache, and sweating may be associated with the condition. [emedicinehealth.com]

  1. rickettsialpox (n.) mild infectious rickettsial disease caused by a bacterium of the genus Rickettsia transmitted to humans by the bite a mite that lives on rodents; characterized by chills and fever and headache and skin lesions that resemble chickenpox [synonym.com]

  Rat-bite fever It commonly presents with fever, chills, open sore at the site of the bite and rash, which may show red or purple plaques. [wikidoc.org]

• Rigor

  R50.9 ICD-10-CM Diagnosis Code R50.9 Fever, unspecified 2016 2017 2018 2019 Billable/Specific Code Applicable To Fever NOS Fever of unknown origin [FUO] Fever with chills Fever with rigors Hyperpyrexia NOS Persistent fever Pyrexia NOS Kew Garden A79.1 [icd10data.com]

  Because all 4 diseases have similar clinical manifestations, which may include maculopapular rash, fever, headache, rigor, myalgia, and arthralgia ( 1 – 4 ), laboratory investigation is needed to identify the rickettsial etiologic agent. [doi.org]

• Military Personnel

  Seroepidemiology of infections due to spotted fever group rickettsiae and Ehrlichia species in military personnel exposed in areas of the United States where such infections are endemic. J. Infect. Dis. 171 : 1266 -1273. 371. Yu, X., Y. Jin, M. [dx.doi.org]

• Pertussis

  / Bordetella parapertussis Pertussis γ Enterobacteriales ( OX ) Lac Klebsiella pneumoniae Rhinoscleroma, Klebsiella pneumonia Klebsiella granulomatis Granuloma inguinale Klebsiella oxytoca Escherichia coli : Enterotoxigenic Enteroinvasive Enterohemorrhagic [en.wikipedia.org]

• Petechiae

  Meningitis It commonly presents with headache, nuchal rigidity, fever, petechiae and altered mental status. [wikidoc.org]

  These lesions are 0.5–1.5 cm wide, with a central area of ulcerated or scabbed skin surrounded by a halo of erythema ( A and B ) or petechiae (C). Panel D shows multiple eschars on patient 4. [doi.org]

  Hemorrhagic manifestations, including petechiae and suffusions, were frequent (69.5%). The case fatality rate was 30% (R. N. Angerami, M. R. Resende, S. B. Stuchi Raquel, G. Katz, E. Nascimento, and L. J. Silva, Abstr. 4th Int. Conf. [dx.doi.org]

• Eczema

  In about 10% of the cases, eczema develops around the lesions. They may occasionally be complicated by secondary bacterial infections. [wikidoc.org]

  […] papulovesicular eruption and that may be confused with rickettsialpox include infectious mononucleosis, several enterovirus in- fections (such as echovirus types 9 and 16, coxsackievi- rus A types 9 and 16, and coxsackievirus B type 5), gono- coccemia, and eczema [slideshare.net]

• Cutaneous Manifestation

  Both of these cutaneous manifestations may be mimicked by infectious diseases that have been designated as bioterrorist agents by the United States Centers for Diseases Control and Prevention: the former by anthrax, and the latter by smallpox. [ncbi.nlm.nih.gov]

• Angiomatosis

  Ehrlichia ewingii Ehrlichiosis ewingii infection Rhizobiales Brucellaceae Brucella abortus Brucellosis Bartonellaceae Bartonellosis : Bartonella henselae Cat-scratch disease Bartonella quintana Trench fever Either B. henselae or B. quintana Bacillary angiomatosis [en.wikipedia.org]

• Chancroid

  Proteus vulgaris Yersinia pestis Plague / Bubonic plague Yersinia enterocolitica Yersiniosis Yersinia pseudotuberculosis Far East scarlet-like fever Pasteurellales Haemophilus : H. influenzae Haemophilus meningitis Brazilian purpuric fever H. ducreyi Chancroid [en.wikipedia.org]

• Headache

  Patents experience fevers, sweats, headaches, and a vesicular eruption over the trunk and extremities. The palms and soles are spared. An eschar results at the spot of the mite bite. Tetracycline is the treatment of choice. [ncbi.nlm.nih.gov]

  Meningitis It commonly presents with headache, nuchal rigidity, fever, petechiae and altered mental status. [wikidoc.org]

  Rickettsialpox causes rash, fever, chills, heavy sweating, headache, eye pain (especially when exposed to light), weakness, and achy muscles. [encyclopedia.com]

  Fever, chills, swollen lymph nodes, rash, muscle pain, headache, and sweating may be associated with the condition. [emedicinehealth.com]

• Vertigo

  Rarely there may be associated neurological symptoms like photophobia, vertigo, retro-orbital pain, neck stiffness. Cases of hepatitis have also been reported. Rickettsialpox is a self-limiting disease and not associated with mortality. [symptoma.com]

Clinical suspicion, the geographical residence of the patient and a history of recent travel to areas known to have a high incidence of rickettsial infection is essential for diagnosis. Although laboratory tests are not diagnostic, a complete blood count with differential count may reveal leukopenia with relative lymphocytosis, and thrombocytopenia while urinalysis may show mild proteinuria. The diagnosis is established with indirect immunofluorescence assay (IFA) and polymerase chain reaction (PCR) of a biopsy specimen of the rash at a special reference laboratory [10] as only they can differentiate between the various rickettsial species [11]. Amplification of the bacterial genome with PCR can be confirmatory if IFA is inconclusive [7].

Cutaneous biopsies are rarely required for diagnosis. But if obtained, then histology of tissues stained with Giemsa may show very tiny coccobacillus intracellular bacteria with mononuclear cells infiltrating the epidermis. There may be dermal and epidermal necrosis, perivascular inflammation, red blood cell extravasation and vacuolar degeneration in the basal cell layers. It is difficult to grow rickettsia in cultures and therefore, cultures are not helpful in the workup.

Imaging studies are not useful in diagnosing rickettsialpox although they may be warranted in the case of suspected organ involvement and if complications of the disease develop.

• Citrobacter Koseri

  koseri / Citrobacter freundii Lac H2S Salmonella enterica Typhoid fever, Paratyphoid fever, Salmonellosis H2S Shigella dysenteriae / sonnei / flexneri / boydii Shigellosis, Bacillary dysentery Proteus mirabilis / Proteus vulgaris Yersinia pestis Plague [en.wikipedia.org]

• Vibrio Vulnificus

  vulnificus Vibrio parahaemolyticus Vibrio alginolyticus Plesiomonas shigelloides Pseudomonadales Pseudomonas aeruginosa Pseudomonas infection Moraxella catarrhalis Acinetobacter baumannii Xanthomonadaceae Stenotrophomonas maltophilia Cardiobacteriaceae [en.wikipedia.org]

• Vibrio Parahaemolyticus

  parahaemolyticus Vibrio alginolyticus Plesiomonas shigelloides Pseudomonadales Pseudomonas aeruginosa Pseudomonas infection Moraxella catarrhalis Acinetobacter baumannii Xanthomonadaceae Stenotrophomonas maltophilia Cardiobacteriaceae Cardiobacterium [en.wikipedia.org]

• Eikenella

  Bartonella bacilliformis Carrion's disease, Verruga peruana β Neisseriales M Neisseria meningitidis/meningococcus Meningococcal disease, Waterhouse–Friderichsen syndrome, Meningococcal septicaemia M Neisseria gonorrhoeae/gonococcus Gonorrhea ungrouped: Eikenella [en.wikipedia.org]

• Bordetella Pertussis

  […] gonorrhoeae/gonococcus Gonorrhea ungrouped: Eikenella corrodens / Kingella kingae HACEK Chromobacterium violaceum Chromobacteriosis infection Burkholderiales Burkholderia pseudomallei Melioidosis Burkholderia mallei Glanders Burkholderia cepacia complex Bordetella [en.wikipedia.org]

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3. Paddock CD, Koss T, Eremeeva ME, et al. Isolation of Rickettsia akari from eschars of patients with rickettsialpox. Am J Trop Med Hyg 2006;75:732–8.
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7. Zavala-Castro JE, Zavala-Velazquez JE, Peniche-Lara GF, Sulu Uicab JE. Human rickettsialpox, southeastern Mexico. Emerg Infect Dis 2009; 15:1665–7.
8. Madison G, Kim-Schluger L, Braverman S, Nicholson WL, Wormser GP. Hepatitis in association with rickettsialpox. Vector Borne Zoonotic Dis 2008; 8:111–5.
9. Galvao MA, Mafra CL, Chamone Ch B, et al. Clinical and laboratorial evidence of Rickettsia felis infections in Latin America. Rev Soc Bras Med Trop 2004;37:238–40
10. Trout Fryxell RT, Steelman CD, Szalanski AL, et al. Molecular Detection of Rickettsia Species Within Ticks (Acari: Ixodidae) Collected from Arkansas, United States. J Med Entomol. 2015 May. 52 (3):500-8.
11. Renvoise A, van't Wout JW, van der Schroeff J-G, et al. A case of rickettsialpox in Northern Europe. International Journal of Infectious Diseases. 2012; 16: e221-e2