The Journal of Emergency Medicine, Vol. 41, No. 4, pp. 362e365, 2011Copyright � 2011 Elsevier Inc.

Printed in the USA. All rights reserved0736-4679/$ - see front matter

doi:10.1016/j.jemermed.2010.05.030

RECEIVED: 2 FebACCEPTED: 18 M

OriginalContributions

SEVERE IRON DEFICIENCY ANEMIA AND LICE INFESTATION

David A. Guss, MD, Mark Koenig, MD, and Edward M. Castillo, PHD

Department of Emergency Medicine, University of California, San Diego Medical Center, San Diego, CaliforniaReprint Address: David A. Guss, MD, Department of Emergency Medicine, UCSD Medical Center 8676, 200 West Arbor Drive,

San Diego, CA 92103-8676

, AbstractdBackground: Lice infestation is a commonlyencountered disorder in emergencymedicine. The louse sur-vives from a blood meal from its host; hence, iron deficiencyanemia is a theoretic possibility. A limited number of reportsof severe iron deficiency anemia have appeared in the veter-inary literature, but a thorough review of the medical liter-ature did not reveal a single instance in human beings.Objective: We report a small case series of patients withheavy louse infestation and profound iron deficiency anemia.Case report: The index case along with two other cases dis-covered from an exhaustive search of 4 years of the institu-tion’s Emergency Department records all had heavyinfestation with head and body lice. Laboratory evaluationrevealed serum hemoglobin levels under 6 gm/dL, low se-rum ferritin levels, and microcytic red blood cell indices.All patients were admitted to the hospital, received transfu-sions, and had evaluation of their anemia. No patient hadevidence of gastrointestinal blood loss or alternative expla-nation for their anemia. Conclusions: Although cause andeffect cannot be established from this case series, to thebest of our knowledge, this is the first published evidenceof a provocative association of louse infestation and severeiron deficiency anemia in humans. � 2011 Elsevier Inc.

, Keywordsdanemia; louse; iron deficiency

INTRODUCTION

Pediculus humanus corporis and capitus are common in-festations. These lice survive from a bloodmeal from their

ruary 2010; FINAL SUBMISSION RECEIVED: 7 Apriay 2010

362

hosts. The veterinary literature has a series of reports ofprofound anemia in cattle and one report of anemia inspider monkeys attributed to species-specific infestationwith lice (1e6). A recent case of a patient with profoundiron deficiency anemia associated with heavy louseinfestation without other apparent cause for anemiaraised the question of a possible causative relationshipbetween louse infestation and anemia. A search of themedical literature employing PubMed, EMBASE, andGoogle Scholar with keywords “pediculosis,” “lice,” and“louse,” each coupled with the term “anemia” datingback to 1953 did not reveal a single case of anemiaassociated with louse infestation. Furthermore, a reviewof several recent major texts in the field of infectiousdisease and parasitology did not reveal any mention oflouse infestation and anemia in humans (7e10). To thebest of our knowledge, presented herein is the index caseof severe iron deficiency anemia associated with heavylouse infestation. This case led to a 4-year review of anemergency department (ED) database for additionalcases. The findings of that review are presented as well.

INDEX CASE SYNOPSIS

A 61-year-old man presented to the ED with a complaintof lightheadedness and generalized weakness of 1 weekduration. The patient was homeless and was transportedby paramedics. He denied fever, chest pain, cough, ab-dominal pain, vomiting, diarrhea, or bloody or darkly col-ored stool. Past medical history was notable for cellulitis.

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Severe Iron Deficiency Anemia and Lice Infestation 363

The patient was not taking prescription medications anddenied illicit drug use. Physical examination revealeda regular pulse of 89 beats/min, blood pressure 130/71 mmHg, oral temperature 36.8 �C (98.2�F), respiration16 breaths/min, and oxygen saturation 98%. The patientwas disheveled and his clothing was covered with lice.Head and neck examination were normal with the excep-tion of the palpebral conjunctiva, which was noted to bepale. Heart examination revealed a regular rhythm with-out murmur or gallop; the lungs were clear to ausculta-tion. The abdomen was soft without palpable mass ortenderness. Rectal examination yielded a brown stoolthat was negative for occult blood. The skin did not revealany discoloration or rash, and was remarkable for numer-ous live lice on the body and scalp, with louse nits in thehair. Routine laboratory studies revealed normal electro-lytes, blood urea nitrogen, and creatinine. The hemoglo-bin was 4.0 gm/dL (normal range 14e17 gm/dL),hematocrit 14.6% (normal range 40e50%), mean cellvolume (MCV) 60.6 um3 (normal range 82e98 um3),and white blood cell count 10,100/mL (normal range4.1e11.0� 1000/mm3). The patient was shaved, bathed,and treated with permethrin cream and shampoo. He wasadmitted to the hospital for transfusion and further evalu-ation. During his hospitalization he received a total of5 units of packed red blood cells. Work-up of anemia re-vealed serum ferritin of 6 ng/dL (normal range 22e322ng/dL) with normal red blood cell (RBC) folate, vitaminB12, and haptoglobin levels. Upper gastrointestinal en-doscopy and colonoscopy were performed and therewere no abnormalities identified. During hospitalizationthe patient had a febrile episode and grew methicillin-sensitive Staphylococcus aureus from his blood. Cardiacultrasound was negative for valvular disease or vegeta-tions. He received 6 days of antibiotics and was dis-charged on vitamin and iron supplements along withsulfamethoxazole trimethoprim.

ADDITIONAL CASES

To determine if therewere other cases of severe anemia as-sociatedwith louse infestation, a review of ED recordswasconducted. After approval by the institutional reviewboard, all ED records from October 2004 to June 2008were searched for the presence of a hemoglobin test andany one of the key words, pediculosis, louse, lice, infesta-tion, and permethrin, and then cross-referenced againstlaboratory values of hemoglobin# 6 gm/dL. This valueof hemoglobin was utilized to identify the most dramaticcases of anemia to assure that identified patients werelikely to have been admitted and evaluated for theiranemia. The inpatient records of ED cases that met theinclusion criteria of anemia as defined by hemoglobin# 6 gm/dL and description of infestation by lice in the

ED record were reviewed. Data collected included demo-graphics of age, gender, social aspects of homelessness, ordescriptors of drug or alcohol abuse. Vital signs, physicalfindings, and descriptors of louse infestation by nursingor physician staff were recorded. Laboratory data includedcomplete blood count and any laboratory values thatmightbe reflective of an evaluation of anemia. This includedcomplete blood count, serum iron, serum ferritin, transfer-rin, serumB12 level, serum folate, and serum haptoglobin.Any investigation performed to assess for gastrointestinalor other blood loss, such as upper endoscopy or colono-scopy, was recorded as well.

During the study period therewere 134,029 visits to thestudy ED. There were a total of 102 patients with a hemo-globin test and one of the qualifying key words over thestudy period. After a review of patient records, 5 patients(B, C, D, E, and F) beyond the index case (A) were iden-tified that met the inclusion criteria, and all were admittedto the hospital from the ED. The ages of the additionalcases ranged from 42 to 55 years old, and three weremale. Chief complaints upon arrival were one each forweakness, rash, shortness of breath, assault, and abdomi-nal pain. Four patients arrived by ambulance and one bypolice car. Four patients (B through E) were describedby one or more providers as being covered in “bugs” or“lice”; one patient (F) self-described infestation by lice.This patient never had any health provider documentationto support louse infestation. All patients described byhealth providers as being infested were treated with per-methrin 5% lotion or solution while in the ED. The EDchart review indicated that all patients admitted to beingchronically homeless and to use alcohol in excess. Allpatients denied signs or symptoms of gastrointestinal orother bleeding and no patient had bleeding during theirhospitalization. A complete summary of laboratoryvalues, transfusion history, and any endoscopic proce-dures performed during their ED stay or subsequenthospitalization are found in Table 1.

In this case series, 5 (A through E) patients were iden-tified with heavy louse infestation based upon health careprovider description and need for permethrin during theED stay and severe anemia characterized by hemoglo-bin < 6 gm/dL. Patient F was not confirmed to be infestedwith lice and was included in the initial case retrieval dueto the nature of the keyword search employed to identifypossible cases. Four patients (A, B, D, and E) had clearcharacteristics of iron deficiency anemia based uponlow red blood cell MCV and mean cell hemoglobin con-centration, and low serum ferritin levels. All patientswere evaluated for blood loss with one or more stoolspecimens for occult blood, and 4 of 5 patients had upperand lower endoscopies during their hospitalization. Allpatients had negative tests for occult blood. Patient Ddid demonstrate changes characteristic of hypertrophic

Table 1. Subject Characteristics and Test Results

Category Normal Values

Patient A B C D E FGender M F M M M FAge 61 55 43 52 50 54Homeless Y Y Y Y Y YAlcohol Y Y Y Y Y YChief complaint Weakness SOB Rash Weakness Assault Abd. painBlood in stools N N - N N NHeavy menstruation NA N NA NA NA NTemperature 98.2 97.4 99.3 97.6 98.5 98.6Blood pressure, mm Hg 130/71 104/69 130/80 102/55 117/63 112/70Pulse, beats/min 89 106 120 100 107 103Respiratory rate,

breaths/min16 18 16 18 20 18

Oxygen saturation 98 100 98 100 100 100History of gastrointestinal

bleedingN N N N N

Albumin 3.3e5.0 gm/dL 2.9 3.2 3.3 2.2 2.9Bicarbonate 24e31 mEq/L 27 20 21 22 25Hemoglobin 14e17 gm/dL 4 3.2 5.7 4.7 4.4 5.7Hematocrit 40e50% 14.6 10.3 17.4 16.2 15.5 18.2MCV 82e98 um3 60.6 71 89.7 76 63.8 77.9MCH 27e31 pgm 16.4 22.2 29.7 22 18.1 24.2MCHC 32e37% 27.1 31.3 32.8 29 28.3 31.1RDW 10e15% 20.8 23.7 14.1 20.2 20.2 18.2WBC 4.1e11.0� 1000/mm3 10.1 9.4 8.2 9.1 7.7 3Eosinophils 1e3% 30 0 17 0 10 1Transfusion 5 units 7 units 4 units 4 units 4 units 2 unitsFe total 65e175 mg/dL 321 5 15 10 14 12Ferritin 22e322 ng/dL 6 5 19 6 8 11Transferrin 180e329 mg/dL 291 358 286 - 256 -Red cell fol > 145 ng/mL 2186 - - - - -Folate > 2.8 ng/mL 16 13.8 - - -Vitamin B12 211e911 pg/mL 427 678 1082 468 299 485LDH 25e175 iu/L 146 - 294 194 185 -Haptoglobin 16e200 mg/dL 82 - 11.7 133 317 -Occult blood Negative Negative Negative Negative Negative NegativeINR 1.1 1.4 1.1 1.2 1.1 1.1Upper endoscopy Normal Refused Normal Hypertrophic

gastropathy,no bleeding

Small gastriculcer, nobleeding

Not done

Colonoscopy Normal Refused Normal Normal Normal Not done

SOB = shortness of breath; Abd. = abdominal; MCV =mean cell volume; MCH=mean cell hemoglobin; MCHC=mean cell hemoglobinconcentration; RDW= red cell distribution width; WBC=white blood cell count; LDH = lactic dehydrogenase; INR = international normal-ized ratio.

364 D. A. Guss et al.

gastropathy, but no signs of mucosal erosion or bleedingon upper endoscopy. Patient E had a small non-bleedinggastric erosion that the consulting gastroenterologist didnot believe to be the cause of the patient’s anemia. PatientB refused endoscopy and patient C had normal upper andlower endoscopy. Patient C had normal RBC indices,a mildly elevated lactic dehydrogenase, and a depressedserum haptoglobin, all compatible with hemolysis; how-ever, therewere no signs of hemolysis on blood smear. Allof the patients had low serum albumin, and patient B hada slightly prolonged INR. These values are compatiblewith either liver disease or poor nutritional state. It is un-likely that poor nutrition alone was responsible for irondeficiency anemia in the patients identified in this report,but it cannot be excluded as a contributing factor.

DISCUSSION

Louse infestation is an ancient and still common disorder.Nits over 10,000 years old have been identified, and it iscurrently estimated that there are about 12 million casesof pediculosis in the United States annually (11,12).Pediculus humanus capitis is the cause of head lice,Pediculus humanus corporis the cause of body lice, andPhthiris pubis the cause of pubic infestation. A singlestudy conducted by Speare and associates attempted toquantitate the amount of blood a single head louseingests during a single feed (13). The value rangedfrom 0.0000387 mL to 0.0000657 mL in female andmale lice, respectively (13). Although never studied, thebody louse, generally larger than P. humanus capitis,

Severe Iron Deficiency Anemia and Lice Infestation 365

might be expected to ingest a somewhat larger amount.Although the amount of blood ingested during a singlefeed is extremely small, a heavily infested individualover an extended period of time might be expected tobe susceptible to iron deficiency anemia. This might par-ticularly be the case in an individual with poor nutrition oradditional risk factors for iron deficiency anemia such asslow gastrointestinal bleeding. Considering the animalreports of iron deficiency anemia consequent to heavylouse infestation, it is not unexpected that blood-suckingP. humanus capitis and corporis could have a sim-ilar effect in humans. It was surprising that the extensiveliterature review did not identify a single article ortextbook notation that anemia was associated with louseinfestation in humans (7e10).

In this case series, 3 patients (A, B, and D) had provoc-ative evidence for a causal relationship between louseinfestation and severe iron deficiency anemia. Gastroin-testinal blood loss was very unlikely given the clinicalcourse and negative inpatient evaluation along with theconsidered opinions of the treating hospitalists and gas-troenterologists. A fourth patient (E) could be consideredpart of this series; however, upper endoscopy in thispatient did reveal a small non-bleeding gastric ulcerwith a clean base. Although it was the expressed opinionof the consulting gastroenterology consultant that thiswas not a factor in the patient’s anemia, we will not in-clude him as a representative case. Patient C may havehad a hemolytic anemia, but a formal diagnosis of thiswas not established during the patient’s hospitalization.Although 3 patients out of 134,000 ED visits during thestudy period is a small number, it should be rememberedthat the search strategy targeted only those with profoundanemia. If milder degrees of anemia had been searchedfor, it is likely that more cases would have been identified.As it is not routine practice to obtain a complete bloodcount on patients infested with lice, it is possible thatthe number of patients with anemia due to pediculosisis higher.

CONCLUSION

This series of 3 patients provides provocative evidence thatheavy and presumed extended periods of louse infestationcan cause severe iron deficiency anemia. In the UnitedStates, anemia is likely to be encountered more oftenthan the established complications of louse infestationsuch as typhus, trench fever, and relapsing fever. Thisreport should heighten suspicion for anemia in patientswith severe pediculosis, which, in turn, may identifymore cases and further validation of this newly reportedclinical syndrome.

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