Emergency physicians are challenged to maintain an appropriate level of suspicion for acute pathology in the face of a seemingly benign complaint. Many times, a benign symptom represents a harmless ailment. But occasionally, it is a hint to a much more serious problem. Always keep the differential diagnosis broad, asking yourself, “What else can be causing this? What serious, life-threatening things can I be missing?” A 43-year-old black man presented with the hiccups of 3 weeks duration. The hiccups were constant, not affected by eating, and not relieved with Maalox or Gas-X. He had no associated chest pain, abdominal pain, nausea, vomiting, change in his bowel movements, or fever. He denied any past medical history, although he had no primary care physician. He reported that he smoked one pack of cigarettes per day and drank beer socially on the weekends. His physical examination included stable vital signs. His pupils were equal, round, and reactive to light, with non-icteric sclera. He had no oral lesions or jugular venous distention. His lungs were clear. His heart had a regular rate and rhythm without murmurs. His abdomen was soft and non-tender, with normal bowel sounds and no organomegaly. His extremities were without edema, and he had a non-focal neurologic examination. Skin examination revealed a localized rash, shown in Figure 1. When asked about it, the patient said that it had been there for several weeks and was not pruritic. He had never had any of these symptoms before. What is the diagnosis and treatment? This patient had a vesicular rash on his right lateral neck. Herpes zoster had affected his dermatomes in a C3-C4-C5 distribution. The nerve involved was the right phrenic nerve, which also innervated his diaphragm. Herpes zoster infections include a primary course, typically a chicken pox infection during childhood, followed by a latent period, where the virus remains present in cranial or dorsal root ganglia, followed by one or more episodes of reactivation. Reactivation typically presents with a painful vesicular rash, and can produce complications such as post-herpetic neuralgia, paralysis, and encephalitis (1Paudyal B.P. Karki A. Zimmerman M. Kayastha G. Acharya P. Hemidiaphragmatic paralysis: a rare complication of cervical herpes zoster.Kathmandu Univ Med J (KUMJ). 2006; 4: 246-248PubMed Google Scholar). In this patient's case, the reactivation of herpes zoster was causing irritation of the right diaphragm (Figure 2), causing his symptom of hiccups. Herpes zoster infection of the phrenic nerve is very rare. There are only four cases of hiccups being caused by herpes zoster reported in the literature (2Brooks W.D.W. Zoster, hiccup and varicella.Br Med J. 1931; 2: 298-299Crossref PubMed Google Scholar, 3Efrati P. Obstinate hiccup as a prodromal symptom in thoracic zoster.Neurology. 1956; 6: 601-602Crossref PubMed Google Scholar, 4Berlin A.L. Muhn C.Y. Billick R.C. Hiccups, eructation, and other uncommon prodromal manifestations of herpes zoster.J Am Acad Dermatol. 2003; 49: 1121-1124Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar, 5Reddy B.V. Sethi G. Aggarwal A. Persistent hiccups: a rare prodromal manifestation of herpes zoster.Indian J Dermatol Venereol Leprol. 2007; 73: 352-353Crossref PubMed Scopus (7) Google Scholar). Diagnosis is made clinically based on symptoms and presence of the characteristic rash, or evidence of a previous rash (i.e., hyperpigmented scarring) (1Paudyal B.P. Karki A. Zimmerman M. Kayastha G. Acharya P. Hemidiaphragmatic paralysis: a rare complication of cervical herpes zoster.Kathmandu Univ Med J (KUMJ). 2006; 4: 246-248PubMed Google Scholar, 6Melcher W.L. Dietrich R.A. Whitlock W.L. Herpes zoster phrenic neuritis with respiratory failure.West J Med. 1990; 152: 192-194PubMed Google Scholar). Phrenic nerve involvement can be confirmed with elevated hemidiaphragm on chest X-ray study or paradoxical hemidiaphragm movement on fluoroscopy. Untreated, it has been known to progress to respiratory failure requiring ventilator support due to paralysis of the hemidiaphragm (6Melcher W.L. Dietrich R.A. Whitlock W.L. Herpes zoster phrenic neuritis with respiratory failure.West J Med. 1990; 152: 192-194PubMed Google Scholar). Severely immunocompromised patients who are diagnosed with herpes zoster affecting multiple dermatomes should be admitted for intravenous antivirals such as acyclovir (7Krause RS. Herpes zoster. Emedicine > Emergency Medicine > Infectious Disease. Available at: http://emedicine.medscape.com/article/788310-treatment. Accessed March 11, 2011.Google Scholar). See Table 1 for differential diagnoses of phrenic nerve hemiparesis (8Kamangar N. Diaphragmatic paralysis. Emedicine > Medscape > Diaphragmatic Paralysis > Clinical Presentation. Available at: http://emedicine.medscape.com/article/298200-clinical#a0218. Accessed August 22, 2011.Google Scholar, 9Celli B. Causes and diagnosis of unilateral diaphragmatic paralysis and eventration. UptoDate. Available at: http://www.uptodate.com/contents/causes-and-diagnosis-of-unilateral-diaphragmatic-paralysis-and-eventration?source=search_result&selectedTitle=2%7E150. Accessed August 22, 2011.Google Scholar, 10Meyers BF, Kozower BD. Paralyzed diaphragm (2005). ACS Surgery: Principles and Practice > Thorax. Available at: http://www.acssurgery.com/acs/pdf/ACS0406.pdf. Accessed August 22, 2011.Google Scholar).Table 1Differential Diagnosis for Phrenic Nerve Hemiparesis 8Kamangar N. Diaphragmatic paralysis. Emedicine > Medscape > Diaphragmatic Paralysis > Clinical Presentation. Available at: http://emedicine.medscape.com/article/298200-clinical#a0218. Accessed August 22, 2011.Google Scholar, 9Celli B. Causes and diagnosis of unilateral diaphragmatic paralysis and eventration. UptoDate. Available at: http://www.uptodate.com/contents/causes-and-diagnosis-of-unilateral-diaphragmatic-paralysis-and-eventration?source=search_result&selectedTitle=2%7E150. Accessed August 22, 2011.Google Scholar, 10Meyers BF, Kozower BD. Paralyzed diaphragm (2005). ACS Surgery: Principles and Practice > Thorax. Available at: http://www.acssurgery.com/acs/pdf/ACS0406.pdf. Accessed August 22, 2011.Google ScholarMalignancy (e.g., metastatic lung, cervical mass)TraumaSurgical injuryCervical spondylolisthesisAmyotrophic lateral sclerosis (ALS)Viral: Guillain Barré, poliomyelitis, herpes zosterPneumoniaDiabetesConnective tissue diseaseEmboliBrachial plexopathies (inflammatory, congenital) Open table in a new tab The patient was started on intravenous acyclovir and admitted to the hospital. He was tested for previously undiagnosed human immunodeficiency virus disease, and this result came back positive.