My Case Study Solution

Transcription

1 My Case Study Solution By Amanda Denny John, a 28 year old engineer presents to his primary doctor with a 3 day history of flu-like symptoms. He has a body aches, stomach pain, chills, and mild diarrhea. John has a sore throat so the doctor performs a culture swab in the office and the results are negative for Streptococcus bacteria. The doctor diagnoses him with a virus but does not prescribe him any antibiotics as they will not help if he does not have a bacterial infection. She instructs John to take Ibuprofen for the body aches and stick to a BRAT diet for a few days to help his upset stomach and diarrhea. John gains a little energy two days later on a hot summer day so he decides to work in his yard trimming a few weeds with his shirt off. This made John exhausted quickly and he was promptly back inside on the couch. Over the next few days John s flu-symptoms worsen and he develops a linear rash around his trunk and flank. Looking like contact dermatitis to a plant, his primary doctor suspects John brushed up against poison ivy or poison oak while working in his yard. She prescribes him a Prednisone taper and sends him home. The next day the rash on John s trunk develops into small, erythematus blisters with clear fluid. They are only on one half of his body and are painful. He describes them as piercing needles in his skin. Not a superficial pain but a deep, severe, nerve pain. When John lifted up his shirt this is what the doctor saw. 1. What is your differential diagnosis? My first suspicion is shingles. This is because of the linear fluid filled vesicles and John s description that they feel like piercing needles in his skin. [1] This deep nerve pain is characteristic of this disease. My second diagnosis would be poison oak or poison ivy. This is because of the linear pattern of the rash after working in the yard. This can be dismissed because poison oak and poison ivy do not usually cause the

2 patient to feel sick as in John s case. [2] The third diagnosis I would suspect is generalized urticaria. These red welts on the skin could be confused with shingles but this suspicion can be disregarded as his rash is not itchy and urticaria does not usually cause sickness. [3] My third diagnosis I would assume is impetigo because of the fluid filled blisters but this can be dismissed because it is most prevalent on the face and folds of the skin and John s rash is on his trunk. [4] Impetigo is not often painful just cosmetically displeasing. My last diagnosis I would suspect is psoriasis because of the red, raised rash. This is quickly disregarded because psoriasis is often red plaques with silver-white scale. This is not characteristic of John s rash. [5] 2. What disease does John have? Name the etiologic agent. What disease did John have as a child that lead to this disease as an adult? John has shingles, also called herpes zoster. The main etiologic agent is the varicella zoster virus. [6] John most likely had chicken pox as a child and recovered with no symptoms. The virus then travels to nerve cells called dorsal root ganglia. [6] These are bundles of nerves that transmit sensory information from the skin to the brain. [6] Here, the virus hides from the immune system and stays dormant (inactive) in his body throughout his teens and twenties until it was reactivated at age 28 causing his shingles outbreak. [6] 3. Who is at most risk for contracting the disease? Shingles affects one out of every 3 adults, translating to approximately 1 million cases each year in the U.S. Individuals who have had chickenpox as a child are the most at risk population for having shingles later in life. [6] There are certain factors that increase the risk of a shingles outbreak including increased age, immune system suppression, cancer, and taking immunosuppresants. [6] As we age our risk for shingles increases as well as our risk for Postherpetic Neuralgia. People who have damaged immune systems from HIV/AIDS or childhood cancers area at increased risk for herpes zoster. [6] Cancer can also increase the risk of shingles especially those with Hodgkin s lymphoma and those on chemotherapy. Patients taking immunosuppressant drugs for rheumatoid arthritis, lupus, diabetes, or psoriasis can also increase the risk of herpes zoster. [6] Only approximately 6% of shingles cases occur a second time. Recent evidence suggests the first zoster episode may boost the immune system to ward off another infection. [6] 4. What are the 2 stages of this disease and which one is John in when he was diagnosed? There are 2 stages of shingles. The Prodromal Stage, the Active Stage. The Prodromal Stage occurs before the rash appears. This is when the patient may have flu-like symptoms such as chills, stomach pain, or diarrhea. [7] They may also have swelling or tenderness of the lymph nodes which may have been the cause of John s sore throat. [7] Often times, patients in this stage feel a burning or tingling pain around

3 their flank over the affected nerves. This may occur days or weeks before the rash appears on the skin. The Active Stage occurs when a band of small, clear, fluid filled blisters appears. [7] They can occur on any part of the body but will only be present on one half. This rash is described by many as piercing needles in the skin. [7] The blisters usually open and crust over in 5-7 days and heal in 2-4 weeks, although scarring can occur. [7] This is the stage John was in when lifted up his shirt and was finally diagnosed. 5. What is PHN and how does it affect John? PHN is an abbreviation for Postherpetic Neuralgia and is the most common complication of shingles. It usually affects about 25% of shingles patients over age 60. [6] The older the person, the longer PHN is likely to last. [6] PHN usually lasts for at least 30 days but can continue for months or years. [7] Symptoms of PHN include aching burning, or stabbing pain in the area of the shingles rash. This chronic pain can make everyday functions such as eating and sleeping difficult. [7] In some cases it can lead to anxiety and depression. [7] John needs to make sure his doctor treats him for PHN proactively. If not, his intermittent pain can develop into chronic pain and interfere with his daily life. Risk factors that increase the chance of PHN include those who had severe cases of shingles (severe pain and blisters), those whose eyes are affected, and also women have been shown to have a slightly higher rish of PHN. [7] 6. What tests are usually performed to confirm this disease? Be specific! The signs and symptoms of herpes zoster are usually distinctive enough to make an accurate diagnosis once the rash has appeared. The piercing needle feeling is characteristic of herpes zoster. [8] If the rash has not appeared yet shingles can be difficult to diagnose. To diagnose shingles in the laboratory, scraping of cells from the base of the lesion with direct fluorescent antibody staining can identify varcella zoster virus cells. [8] Polymerase chain reaction (PCR) tests can also be used to detect the virus in skin specimens. PCR is not available in all settings but is very sensitive in gaining an accurate diagnosis. [8] Serologic tests can also be used to confirm herpes zoster but there are often challenges in interpreting the results. Patients with shingles often show an IgM response and would be expected to mount a memory IgG response. [8] However, a positive IgM ELISA result could indicate a herpes zoster infection, re-infection, or re-activation. [8] This makes it difficult to distinguish if it is a true infection because the patient may just have a high baseline antibody titer from a prior varicella disease. [8] Another way to confirm shingles is to perform a Tzanck smear. This inexpensive test can be done at bedside but does not diagnose between a herpes zoster infection and a herpes simplex infection. [8] 7. Did John s age have a factor in the misdiagnosis of his illness?

4 Yes, most shingles cases occur in older individuals. According to the National Institute of Health, shingles is 10 times more likely to occur in adults over 60 than in children under 10. [9] Also, PHN is double in those over 70, than those below it. [9] Because John is normally a young, healthy individual it was unlikely the first two times the doctor saw him she would have suspected shingles. [9] When she saw him the third time his fluid filled blisters where distinctive of the disease. 8. If John was a pregnant female could this disease harm the baby? Depending on the severity of the disease and stage of pregnancy it could possibly pose some risks to the unborn child. [9] During the first 30 weeks, maternal chickenpox could lead to congenital malformations. If the mother develops chicken pox between 21 to 5 days before giving birth her new baby can have chicken pox at birth or develop shingles within the first 5 years. [9] This is because a newborn s immune system is not fully functioning in keeping the virus away. 9. How will John be treated? John will most likely be given an antiviral drug to reduce the severity and duration of the attack. He will also be given an anticonvulsant medication to decrease symptoms of PHN. Acyclovir, Famcyclovir, and Valcyclovir are all antiviral drugs that can be given to improve the symptoms of herpes zoster. [6] They are usually given BID for 1-2 weeks for effective treatment. To be effective they should be started within 72 hours of the onset of infection. [6] To decrease the symptoms of PHN, tricyclic antidepressants or anticonvulsants can be given. [6] If a Neurontin protocol is used it is given over a course of 3 weeks, increasing the dose and then tapering off. Often times this is combined with analgesic pain relievers in pain patches and creams. [6] Home remedies that have been shown to provide relief for patients with shingles include cold compresses on the areas affected by the rash as well as oatmeal baths and calamine lotion. [6] Over the counter Benadryl and other antihistamines have been shown to improve itching. [6] 10. Is there a vaccine for this disease? What is its effectiveness? What happened in 2011? There is a vaccine for shingles called Zostavax. It is a stronger version of the chickenpox vaccine and was originally approved for adults 60 and older in May [6] In 2011 the FDA lowered the recommendation at it was approved for adults 50 and older. [6] The vaccine should not be given to those with a weakened immune system. A single shot of the herpes zoster vaccine can reduce the risk of developing shingles by 55%-70% and has also been shown to help prevent or at least decrease the symptoms of PHN. [6] The shingles vaccine is a preventative therapy and should not be given to those who currently have shingles. References

5 [1] WebMD. Shingles Health Center, [2] Mayo Clinic. Poison ivy rash, 8/29/12. [3] Mayo Clinic. Chronic hives, 9/17/11 [4] Berman, K., MedlinePlus. National Institute of Health. Impetigo, 11/20/ [5] American Academy of Dermatology. Psoriasis Signs and Symptoms, [6] Simon, H., University of Maryland Medical Center. Shingles and Chickepox, [7] WebMD. Shingles Symptoms, [8] Centers for Disease Control and Prevention. Shingles (Herpes Zoster), 5/1/ [9] National Institute of Neurological Disorders and Stroke. Shingles: Hope Through Research, 4/16/14