Introduction to Mumps

Also known as infectious or epidemic parotitis, mumps is an acute viral disease caused by a paramyxovirus. It’s most prevalent in unvaccinated children between ages 2 and 12, but it can occur in other age-groups. Infants younger than age 1 seldom get this disease because of passive immunity from maternal antibodies. Peak incidence occurs during late winter and early spring.

The prognosis for complete recovery is good, although mumps sometimes causes complications.

Causes

The mumps paramyxovirus is found in the saliva of an infected person and is transmitted by droplets or by direct contact. The virus is present in the saliva 6 days before to 9 days after onset of parotid gland swelling; the 48-hour period immediately preceding onset of swelling is probably the time of highest communicability.

The incubation period ranges from 14 to 25 days (the average is 18 days). One attack of mumps (even if unilateral) almost always confers lifelong immunity.

Signs and symptoms

Signs and symptoms of mumps vary widely. An estimated 30% of susceptible people have subclinical illness. Mumps usually begins with prodromal signs and symptoms that last for 24 hours; these include myalgia, anorexia, malaise, headache, and low-grade fever, followed by an Continue reading “Introduction to Mumps”

Traumatic Amputation

Traumatic amputation involves the accidental loss of a body part, usually a finger, a toe, an arm, or a leg. In complete amputation, the member is totally severed; in partial amputation, some soft-tissue connection remains.
The prognosis has improved as a result of early improved emergency and critical care management, new surgical techniques, early rehabilitation, prosthesis fitting, and new prosthesis design. New limb reimplantation techniques have been moderately successful, but incomplete nerve regeneration remains a major limiting factor.

Causes

Traumatic amputations usually result directly from accidents at a factory or farm, or from power tools or motor vehicle accidents.
Diagnosis
Any patient with a traumatic amputation requires careful monitoring of vital signs as well as assessment for other traumatic injuries. If amputation involves more than just a finger or a toe, assessment of airway, breathing, and circulation is also required. Because profuse bleeding is Continue reading “Traumatic Amputation”

Urticaria and angioedema

Urticaria, commonly known as hives, is an episodic, usually self-limited skin reaction characterized by local dermal wheals surrounded by an erythematous flare. Angioedema, which can present either subcutaneously or dermally, produces deeper, larger wheals (usually on the hands, feet, lips, genitals, and eyelids) and a more diffuse swelling of loose subcutaneous tissue. Urticaria and angioedema can occur simultaneously, but angioedema may last longer.
Causes
Urticaria and angioedema are common allergic reactions. Causes include allergy to drugs, foods, insect stings and, occasionally, inhalants, such as animal dander and cosmetics, that provoke an immunoglobulin (Ig) E-mediated response to protein allergens. However, certain drugs may cause urticaria without an IgE response.
When urticaria and angioedema are part of an anaphylactic reaction, they almost always persist long after the systemic response has subsided. This occurs because circulation to the skin is inhibited after an allergic reaction, which results in slow histamine reabsorption at the reaction site. Nonallergic urticaria and angioedema are probably also related to histamine release.
External physical stimuli, such as cold (usually in young adults), heat, water, or sunlight, may provoke urticaria and angioedema. Dermographism urticaria develops with varying pressure, usually under tight clothing, and is aggravated by scratching.
Several different mechanisms and underlying disorders may provoke urticaria and angioedema. These include IgE-induced release of mediators from cutaneous mast cells; binding of IgG or IgM, resulting in complement activation; localized or secondary infections such as respiratory infection; neoplastic diseases such as Hodgkin’s disease; connective tissue diseases such as systemic lupus erythematosus; collagen vascular diseases; and psychogenic diseases.
Signs and symptoms
The characteristic features of urticaria are distinct, raised, evanescent dermal wheals surrounded by an erythematous flare. These lesions may vary in size. In cholinergic urticaria, the wheals may be tiny and blanched, surrounded by erythematous flares.
Angioedema characteristically produces nonpitted swelling of deep subcutaneous tissue, usually on the eyelids, lips, genitalia, and mucous membranes. These swellings don’t usually itch but may burn and tingle.
Diagnosis
An accurate patient history can help determine the cause of urticaria. Such a history should Continue reading “Urticaria and angioedema”

Alzheimer’s disease

Also known as primary degenerative dementia, Alzheimer’s disease accounts for more than half of all dementias. An estimated 5% of people over age 65 have a severe form of this disease, and 12% suffer from mild to moderate dementia. Because this is a primary progressive dementia, the prognosis is poor.
Causes
Several factors contribute to the progression of Alzheimer’s disease. They include neurochemical factors, such as deficiencies in acetylcholine (a neurotransmitter), somatostatin, substance P, and norepinephrine; environmental factors, such as aluminum and manganese; viral factors, such as slow-growing central nervous system viruses; trauma; and genetic immunologic factors.
The brain tissue of a patient with Alzheimer’s disease typically shows cortical atrophy, the hallmark features being neurofibrillary tangles, neuritic plaques, and granulovascular degeneration.
Signs and symptoms
Onset is insidious. Initially, the patient experiences almost imperceptible changes, such as forgetfulness, recent memory loss, difficulty learning and remembering new information, deterioration in personal hygiene and appearance, and an inability to concentrate. Gradually, tasks that require abstract thinking and activities that require judgment become more difficult. Progressive and severe deterioration in memory, language, and motor function results in a loss of coordination and an inability to write or speak.
Personality changes (restlessness, irritability) and nocturnal awakenings are common. Eventually, the patient becomes disoriented, and emotional lability and physical and intellectual disability progress. The patient becomes more susceptible to infection and accidents. Secondary to loss of the cough reflex, pulmonary diseases such as pneumonia may result in death.

Diagnosis
Early diagnosis of Alzheimer’s disease is difficult because the patient’s signs and symptoms are Continue reading “Alzheimer’s disease”

Introduction to Scabies

An age-old skin infection, scabies results from infestation with Sarcoptes scabiei var. hominis (itch mite), which provokes a sensitivity reaction. It occurs worldwide, is predisposed by overcrowding and poor hygiene, and can be endemic.
Causes
Mites can live their entire life cycles in the skin of humans, causing chronic infection. The female mite burrows into the skin to lay her eggs, from which larvae emerge to copulate and then reburrow under the skin.
Transmission of scabies occurs through skin or sexual contact. The adult mite can survive without a human host for only 2 to 3 days.
Signs and symptoms
Typically, scabies causes itching that intensifies at night. Characteristic lesions take many forms but are usually excoriated and may appear as erythematous nodules.
Burrows are threadlike lesions about ¾? (2 cm) long and generally occur between fingers, on flexor surfaces of the wrists, on elbows, in axillary folds, at the waistline, on nipples in females, and on genitalia in males. In infants, the burrows may appear on the head and neck.
Intense scratching can lead to severe excoriation and secondary bacterial infection. Itching may become generalized secondary to sensitization.
Diagnosis
Superficial scraping and examination, under a low-power microscope, of material that has been Continue reading “Introduction to Scabies”

Diabetic complications during pregnancy

Pregnancy places special demands on carbohydrate metabolism and causes the insulin requirement to increase, even in a healthy woman. Consequently, pregnancy may lead to a prediabetic state, to the conversion of an asymptomatic subclinical diabetic state to a clinical one (gestational diabetes occurs in about 1% to 2% of all pregnancies), or to complications in a previously stable diabetic state.
Prevalence of diabetes mellitus increases with age. Maternal and fetal prognoses can be equivalent to those in nondiabetic women if maternal blood glucose is well controlled and ketosis and other complications are prevented. Infant morbidity and mortality depend on recognizing and successfully controlling hypoglycemia, which may develop within hours after delivery.
Causes
In diabetes mellitus, glucose is inadequately used either because insulin isn’t synthesized (as in type 1, insulin-dependent diabetes) or because tissues are resistant to the hormonal action of endogenous insulin (as in type 2, non–insulin-dependent diabetes).
Protective mechanisms
During pregnancy, the fetus relies on maternal glucose as a primary fuel source. Pregnancy triggers protective mechanisms that have anti-insulin effects: increased hormone production (placental lactogen, estrogen, and progesterone), which antagonizes the effects of insulin; degradation of insulin by the placenta; and prolonged elevation of stress hormones (cortisol, epinephrine, and glucagon), which raise blood glucose levels.
In a normal pregnancy, an increase in anti-insulin factors is counterbalanced by an increase in insulin production to maintain normal blood glucose levels. However, women who are prediabetic or diabetic can’t produce sufficient insulin to overcome the insulin antagonist mechanisms of pregnancy, or their tissues are insulin-resistant.
As insulin requirements rise toward term, the patient who is prediabetic may develop gestational diabetes, necessitating dietary management and, possibly, exogenous insulin to achieve glycemic control. The insulin-dependent patient may need increased insulin dosage.

Signs and symptoms

All women should receive diagnostic screening for maternal diabetes mellitus during pregnancy. Continue reading “Diabetic complications during pregnancy”