Материал: 100_Cases_in_Clinical_Medicine
ANSWER 38
This patient has erythema nodosum, in this case secondary to previously undiagnosed Crohn’s disease. Erythema nodosum is due to inflammation of the small blood vessels in the deep dermis. Characteristically it affects the shins, but it may also affect the thighs and forearms. The number and size of the lesions is variable. Lesions tend to heal from the centre and spread peripherally. The rash is often preceded by systemic symptoms – fever, malaise and arthralgia. It usually resolves over 3–4 weeks, but persistence or recurrence suggests an underlying disease.
!Diseases linked to erythema nodosum
Streptococcal infection |
Lymphoma/leukaemia |
Tuberculosis |
Sarcoidosis |
Leprosy |
Pregnancy/oral contraceptive |
Glandular fever |
Reaction to sulphonamides |
Histoplasmosis |
Ulcerative colitis |
Coccidioidomycosis |
Crohn’s disease |
The history of mouth ulcers, abdominal pain and diarrhoea strongly suggests that this woman has Crohn’s disease. She should therefore be referred to a gastroenterologist for investigations which should include a small-bowel enema and colonoscopy with biopsies. Treatment of her underlying disease with steroids should cause the erythema nodosum to resolve. With no serious underlying condition, erythema nodosum usually settles with non-steroidal anti-inflammatory drugs.
KEY POINTS
•Patients presenting with erythema nodosum should be investigated for an underlying disease.
•Erythema nodosum is most often seen on the shins but can affect the extensor surface of the forearms or thighs.
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CASE 39: BLISTERS ON THE SKIN
History
An 83-year-old man presents to his general practitioner (GP) having developed multiple blisters on his skin and mouth. The blisters have appeared over 2 days. They tend to burst rapidly to leave a large red sore lesion. The patient has lost about 5 kg in weight over the past 3 months and has a poor appetite. He feels generally unwell. He has also noticed that his bowel habit has become erratic and has noticed some blood in his bowel motions. He has previously been fit and had no significant past medical illnesses. He lives alone and neither smokes nor drinks alcohol. He is taking no regular prescribed medication and has not bought any medication from a pharmacy or health food outlet except some multivitamin tablets since he felt unwell.
Examination
He looks emaciated and unwell. There are blisters spread all over his skin and sores within his mouth. Most of the blisters appear to have burst. His pulse rate is 102/min, irregularly irregular and blood pressure 160/78 mmHg. Examination of his heart and respiratory system is otherwise normal. There is a 6 cm hard nodular liver edge palpable, and also a hard mobile mass present in the left iliac fossa. On rectal examination there is some bright red blood mixed with faecal material on the glove.
INVESTIGATIONS
|
|
Normal |
Haemoglobin |
9.2 g/dL |
13.3–17.7 g/dL |
White cell count |
6.2 % 109/L |
3.9–10.6 % 109/L |
Platelets |
236 % 109/L |
150–440 % 109/L |
Mean corpuscular volume (MCV) |
72 fL |
80–99 fL |
Sodium |
136 mmol/L |
135–145 mmol/L |
Potassium |
3.8 mmol/L |
3.5–5.0 mmol/L |
Urea |
5.2 mmol/L |
2.5–6.7 mmol/L |
Creatinine |
94 &mol/L |
70–120 &mol/L |
Albumin |
32 g/L |
35–50 g/L |
Glucose |
4.3 mmol/L |
4.0–6.0 mmol/L |
Bilirubin |
16 mmol/L |
3–17 mmol/L |
Alanine transaminase |
34 IU/L |
5–35 IU/L |
Alkaline phosphatase |
692 IU/L |
30–300 IU/L |
Blood film: hypochromic, microcytic red cells
Questions
•What is the diagnosis of the skin disease?
•What is the cause of this condition in this patient?
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ANSWER 39
This patient has pemphigus vulgaris. This is a blistering disease where the level of the blister is within the epidermis. The superficial nature of the blister means that the blisters are prone to burst leaving a glistening red base which bleeds easily. The epidermis at the edge of the blister is easily dislodged by sliding pressure (Nikolsky sign). Erosions in the mouth are also common. Associated diseases include carcinoma, lymphoma, thymoma, systemic lupus erythematosus and certain drugs such as penicillamine and captopril.
This elderly man also has hepatomegaly. With the rectal bleeding and microcytic anaemia, it is likely that he has a left-sided colonic neoplasm. The raised alkaline phosphatase suggests secondary metastases in his liver. He needs an ultrasound to image his liver and a colonoscopy to visualize his colon. He should be referred to a surgeon to assess if palliative surgery is appropriate.
Pemphigus is itself life-threatening either due to insensible fluid losses or septicaemia as a result of infection of the exposed blisters. The sore mouth and eroded skin need careful nursing. Treatment is with high doses of corticosteroids, and cytotoxic drugs may need to be added.
!Main differential diagnoses of blistering diseases
•Pemphigoid: the level of bullae is deeper (subepidermal) and the blisters are larger and rupture less often than in pemphigus.
•Erythema multiforme: there are target-shaped lesions with central blisters, often with generalized erythema and mucosal ulceration (Stevens–Johnson syndrome). This is often associated with herpes simplex virus infection, certain drugs, e.g. sulphonamides and neoplasms.
•Dermatitis herpetiformis: there are vesicular lesions over the elbows, knees and face. Vesicles are smaller than blisters (!0.5 cm) and often ruptured by itching. This rash is associated with coeliac disease.
•Miscellaneous blistering disorders: diabetes mellitus, herpes gestationis and familial blistering disorders.
KEY POINTS
•Pemphigus is often associated with underlying serious medical conditions.
•Pemphigus may be fatal usually due to septicaemia as a result of super-added infection of blisters and immunosuppressive treatment.
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CASE 40: PAIN IN THE CHEST AND SHORTNESS OF BREATH
History
A 16-year-old African-Caribbean boy presents to the emergency department complaining of severe chest pain and shortness of breath. He has had a sore throat for a few days and started developing pain in his back and arms which has increased in severity. Six hours prior to admission he suddenly developed right-sided chest pain which is worse on inspiration and associated with marked breathlessness. He has had previous episodes of pains affecting his fingers and back, for which he has taken codeine and ibuprofen. He was born in London and lives with his parents and younger sister. He is attending school and has had no problems there. There is no family history of note.
Examination
He is unwell, febrile 37.8°C and cyanosed. His conjunctivae are pale. Pulse rate is 112/min, regular and blood pressure 136/85 mmHg. His jugular venous pressure is not raised and heart sounds are normal. His respiratory rate is 28/min and there is a right pleural rub audible. Abdominal and neurological examination is normal. There are no rashes on the skin and no joint abnormalities.
INVESTIGATIONS
|
|
Normal |
Haemoglobin |
7.6 g/dL |
13.3–17.7 g/dL |
Mean corpuscular volume (MCV) |
86 fL |
80–99 fL |
White cell count |
16.2 % 109/L |
3.9–10.6 % 109/L |
Platelets |
162 % 109/L |
150–440 % 109/L |
Sodium |
139 mmol/L |
135–145 mmol/L |
Potassium |
4.4 mmol/L |
3.5–5.0 mmol/L |
Urea |
6.2 mmol/L |
2.5–6.7 mmol/L |
Creatinine |
94 &mol/L |
70–120 &mol/L |
Bicarbonate |
24 mmol/L |
24–30 mmol/L |
Arterial blood gases on air: |
|
|
pH |
7.33 |
7.38–7.44 |
pCO2 |
2.6 kPa |
4.7–6.0 kPa |
pO2 |
7.2 kPa |
12.0–14.5 kPa |
Electrocardiogram (ECG): sinus tachycardia |
|
|
Chest X-ray: normal |
|
|
Questions
•What is the likely diagnosis?
•How would you investigate and manage this patient?
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ANSWER 40
This boy has sickle cell disease and presents with his first serious bony/chest crisis. Sickle cell disease occurs mainly in African black populations and sporadically in the Mediterranean and Middle East. Haemoglobin S differs from haemoglobin A by the substitution of valine for glutamic acid at position 6 in the $-chain. Sickled cells have increased mechanical fragility and a shortened survival leading to a haemolytic anaemia, and also can block small vessels leading to tissue infarction. Sickle cell disease has a very variable clinical course due to a combination of reasons including the haemoglobin F (HbF) level and socio-economic factors. It usually presents in early childhood with anaemia and jaundice due to a chronic haemolytic anaemia, or painful hands and feet with inflammation of the fingers due to dactylitis. This patient is having a pulmonary crisis characterized by pleuritic chest pain, shortness of breath and hypoxia. It is usually precipitated by dehydration or infection (in this case, a sore throat). The principal differential diagnoses of a patient presenting with pleuritic pain and breathlessness are pneumonia, pneumothorax and pulmonary emboli.
!Major potential complications of sickle cell disease
•Thrombotic: causing generalized or localized bony pains, abdominal crises, chest crises, neurological signs or priapism.
•Aplastic crises: triggered by parvovirus infection.
•Haemolytic anaemia.
•Sequestration crises in children with rapid enlargement of the liver and spleen, usually in young children.
•Aseptic necrosis: often of the humeral or femoral heads.
•Renal failure due to renal medullary infarction or glomerular disease.
•Hyposplenism due to autoinfarction in childhood.
This patient should be admitted for rest, intravenous fluids, oxygen and adequate analgesia. He has a low arterial pO2 and appears cyanosed. Cyanosis is more difficult to detect in the presence of anaemia. Infection should be treated with antibiotics. A blood film will show sickled erythrocytes and elevated reticulocyte count. The definitive investigation is haemoglobin electrophoresis which will demonstrate HbS, absent HbA and a variable HbF level. Partial exchange transfusion may be needed to reduce the level of his sickle cells to less than 30 per cent. He should be followed up by an expert sickle team since this has been shown to reduce admissions and improve quality of care. He may benefit from long-term hydroxyurea which raises the HbF level and reduces the number of crises.
KEY POINTS
•In African-Caribbean patients, sickle cell disease should be thought of as a cause of chest or abdominal pain.
•Patients with sickle cell disease should be looked after in specialized haematology units with psychological support available.
•Severe thrombotic complications should be treated with partial exchange transfusion.
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