Rubella (German Measles)

Rubella (German measles) is a common communicable infection of children and young adults characterized by a short prodromal period; enlargement of cervical, suboccipital, and postauricular glands; and a rash of approximately 2 to 3 days' duration. The disease has rare sequelae and, were it not for its devastating effect on the fetus, would be of relatively little significance in terms of morbidity or complications.

EPIDEMIOLOGY

Prior to immunization programs, epidemics of rubella were noted at 5- to 7-year intervals. The disease is worldwide in its distribution and tends to occur most frequently during the spring months in North America. During the past decade, fewer than 200 cases were reported in most years in the United States.  It is rare in young infants and is most common in school-age children, adolescents, and young adults. Recent outbreaks in North America have occurred in young men in Latino communities who have come from countries without immunization programs. Through these outbreaks, viruses that are common abroad have been introduced into the United States.  It is spread via the respiratory route, and the period of infectivity extends from the end of the incubation period to the disappearance of the rash. A single attack confers lifelong immunity in most individuals, although subclinical reinfections can be demonstrated by laboratory tests in some “immune” individuals who are subsequently exposed to the wild virus. Two attacks of rubella with rash are most unlikely to be encountered; in such instances, one of the episodes is usually not rubella but is caused by another viral infection.

The virus of rubella may be recovered from the pharynx as early as 7 days before and up to 14 days after the onset of the rash. Viremia is rarely demonstrated after the onset of the rash. 

CLINICAL MANIFESTATIONS

The incubation period ranges between 14 and 21 days and is usually 16 to 18 days. Prodromal signs and symptoms are rare in young children, and the rash usually appears without prior complaint. In older children, adolescents, and adults, low-grade fever, headache, conjunctivitis, sore throat, rhinitis, cough, and lymphadenopathy may precede the rash by 1 to 4 days and disappear rapidly after the rash appears. In some adults, however, these symptoms and signs may persist longer and be more severe, and the infection under such circumstances may be difficult to distinguish from rubeola (measles) unless Koplik's spots, characteristic of measles, are observed. The rash of rubella is first noted on the face  and rapidly spreads to the neck, arms, trunk, and legs. It consists of pink-red macules and papules that are discrete and remain so on the extremities, coalescing on the trunk to give a uniform red blush.

The rash, which usually disappears by the end of 2 or 3 days, clearing first from the face, may occasionally be followed by fine desquamation. This rapid disappearance is in contrast to measles (rubeola), in which the rash persists for longer periods. An enanthem is often seen at the end of the prodromal period or beginning of the rash, consisting of red spots, pinhead in size, scattered over the soft palate. The lymphadenopathy of rubella is striking; it involves all lymph nodes, but enlargement and tenderness are most common in the suboccipital, postauricular, and anterior and posterior cervical nodes. In older children and adults, lymphadenopathy may be noted several days before the rash; but in both children and adults, the enlargement and tenderness are most striking on the first day of the rash. Enlargement of glands may persist for days to weeks, but tenderness rapidly subsides. Splenomegaly may occasionally be detected. The fever of rubella is usually of low grade and seldom lasts beyond the first day or two of the eruption except in individuals who have joint involvement, in whom fever may persist. Arthritis caused by rubella occurs much more frequently in adults than in children, and is usually first noted as the rash fades. Small and large joints may become painful, with or without swelling, possibly simulating rheumatic fever or rheumatoid arthritis. In one epidemic, joint involvement was seen in 25 percent of children younger than 11 of years age and in 52 percent of patients 11 years of age or older. 4 Striking effusions into joints have been reported. The arthritis of rubella usually lasts 1 to 2 weeks but occasionally may persist for longer periods or may be recurrent.

COMPLICATIONS

Rubella is essentially a benign disease. Rarely, it may produce an encephalitis, which tends to be mild and is usually followed by complete recovery and no effect on intellectual function. Thrombocytopenic purpura, which may result from rubella, may be accompanied by epistaxis, petechiae, ecchymoses, intestinal hemorrhage, and hematuria. These manifestations frequently clear within a month of onset but may occasionally persist for longer periods. Rarely, a peripheral neuritis may follow rubella.

LABORATORY FINDINGS

The white blood cell count is usually low but may be normal. Increased numbers of atypical lymphocytes may be noted, and in some cases, increased numbers of plasma cells have been reported. Among patients with meningoencephalitis, varying numbers of lymphocytes may be found in the cerebrospinal fluid (CSF).

INSTRUMENTAL AND LABORATORY PROCEDURES IN DERMATOLOGIC DIAGNOSIS

Aids to Dermatologic Diagnosis: Clinical, Instrumental, and Laboratory

Magnification: To examine the skin surface critically and to detect the fine morphologic detail of skin lesions it is necessary to use a hand lens magnifier (preferably 7×); also, a better image is obtained following application of a drop of mineral oil to the lesion. Magnification is especially helpful in the diagnosis of lupus erythematosus (follicular plugging and atrophy), lichen planus (Wickham's striae), basal cell carcinomas (translucence and delicate telangiectasia), and early malignant melanoma (subtle changes in color, especially gray, slate, or blue). Hand-held magnifying instruments with built-in lighting and a magnification of 10× to 30× have recently become available and these permit better visualization of lesions when used with a drop of oil. Using this small optical instrument or the larger binocular microscope—this technique is called epiluminescence microscopy—facilitates the distinction of benign and malignant pigmented neoplasms.

Wood's lamp (longwave ultraviolet light, “black” light) is essential for the clinical diagnosis of certain skin and hair diseases and of porphyria. Longwave ultraviolet radiation is obtained by fitting a high-pressure mercury lamp with a specially compounded filter made of nickel oxide and silica (Wood's filter); this filter is opaque to all light except for a band between 320 and 400 nm. When using the Wood's lamp, it is essential for the examiner to become dark-adapted in order to see the contrasts clearly. When the ultraviolet waves emitted by Wood's lamp impinge on the skin, a visible fluorescence occurs. Wood's lamp is particularly useful in the detection of the fluorescence of dermatophytosis ( Microsporum) in the hair shaft (green) and of erythrasma (coral red) on the skin. Wood's lamp also helps to estimate the variation in the “whiteness” of lesions in relation to the normal skin color, in dark-skinned and especially in fair-skinned persons; for example, the lesions seen in hypomelanotic macules in tuberous sclerosis and in tinea versicolor are not as white as the macules present in vitiligo, which are typically amelanotic. Circumscribed hypermelanosis, such as ephelides and melasma, is much more evident under Wood's lamp, and in lentigo maligna melanoma and acrolentiginous melanoma the Wood's lamp can be used to detect the total extent of the lesion as a guide to total excision. Melanin in the dermis, as in a Mongolian sacral spot, does not become accentuated under Wood's lamp. Therefore, it is possible to localize the site of melanin (epidermal or dermal) by use of the Wood's lamp; this phenomenon is not evident in patients with brown or black skin. The technique is as follows: a grading (minimal, moderate, marked) of the degree of pigmentation is made with visible light and compared with a grading of the degree of color change when examined with Wood's lamp. In epidermal melanin pigmentation the pigment grade increases from minimal to marked, but dermal melanin has the same degree of pigment in both visible light and Wood's lamp illumination.

Diascopy consists of firmly pressing a transparent, hard, flat object (such as a hand lens or two microscope slides) over the surface of a skin lesion. The examiner will find this procedure of special value in determining whether the red color of a macule or papule is due to capillary dilatation (erythema) or to extravasation of blood (purpura). Diascopy is also useful for the detection of the hyaline yellowish-brown color of papules or nodules in sarcoidosis, tuberculosis of the skin, lymphoma, and granuloma annulare.

Pregnancy And Cutaneous Changes

HORMONAL CHANGES IN PREGNANCY

Pregnancy is a time of significant and complex physiologic changes. Some of these changes are due to the de novo production of a variety of protein and steroid hormones by the fetoplacental unit as well as to the increased activity of the maternal pituitary, thyroid, and adrenal glands. The currently recognized hormones produced by the placenta include the protein hormones human chorionic gonadotropin (HCG), human placental lactogen (HPL) or human somatomammotropin, human chorionic thyrotropin, and human chorionic corticotropin, as well as the steroid hormones progesterone and estrogen. A description of the chemistry, function, and metabolism of these hormones is beyond the scope of this chapter, but it should be kept in mind that the production and the serum levels of these hormones are dynamic. For instance, HCG levels peak between the tenth and twelfth weeks of gestation, although they remain elevated throughout pregnancy. The levels of progesterone and estrogen rise throughout the first and second trimesters of pregnancy and plateau during the third trimester. The levels of these hormones are of diagnostic significance in certain obstetric conditions and complications, but their exact impact on cutaneous physiology, as well as their influence on the immunology of the skin and the inflammatory response, is essentially unknown.

CUTANEOUS CHANGES COMMONLY ASSOCIATED WITH PREGNANCY

Although the influences that the individual hormones have on the skin are incompletely understood, it is thought that they are responsible, either primarily or secondarily, for many of the cutaneous changes that normally occur during pregnancy.

Pigmentation

The nipples, areolae, and external genitalia become hyperpigmented during pregnancy. The linea alba becomes the linea nigra. Occasionally, hyperpigmentation is noted in the axillae and the proximal medial portions of the thighs. The most noticeable pigmentary change during pregnancy is the development of a masklike hyperpigmentation of the face, known as chloasma or melasma, in more than 50 percent of women.

This tendency is exacerbated by sun exposure in susceptible individuals and also may be exacerbated by birth control pills in nonpregnant women. Additionally, preexisting nevi or ephelides frequently darken during pregnancy. The degree of hyperpigmentation tends to be related to the skin type of the individual, with lightly complected individuals developing less intense pigmentation. In all these instances, partial or, at times, complete regression of the hyperpigmentation usually occurs gradually after termination of pregnancy. The physiology of the hyperpigmentation appears to be related to the increased production of estrogens and perhaps to increased levels of progesterone or melanocyte-stimulating hormone.

Hair

Mild to moderate hirsutism is seen frequently during pregnancy. The hirsutism tends to resolve shortly after delivery or in some instances in the third trimester. After delivery, the resulting telogen effluvium may be severe, resulting in significant hair loss from 1 to 5 months postpartum. In these instances, regrowth, usually within 1 year, is the rule.

Connective Tissue

The most common change in connective tissue is the development of striae distensae over the abdomen, hips, buttocks, and sometimes the breasts .

Striae distensae occur in up to 90 percent of pregnant women. The exact cause of striae is unknown, although a combination of hormonal factors (e.g., adrenocortical hormones, estrogen, relaxin) associated with increased lateral stress on the connective tissue due to increased size of the various portions of the body is thought to be important. Striae distensae initially appear as pink to purple atrophic bands .

sometimes associated with mild pruritus. After delivery, they become pale and less apparent. Skin tags, also known as molluscum fibrosum gravidarum, often appear on the lateral portions of the neck and axillae during pregnancy and may persist after delivery.

Vascular

Hyperemia is physiologic during pregnancy. This, combined with a tendency toward vascular proliferation, results in a number of common cutaneous changes during pregnancy. Up to two-thirds of women develop palmar erythema and/or spider angiomas during pregnancy.

Vascular distention resulting in part from increased intraabdominal pressure is thought to be responsible for the edema and venous varicosities that commonly occur on the legs and feet. Hemorrhoids also occur for the same reasons. Vascular tumors such as glomus tumors or hemangiomas may appear or enlarge during pregnancy. The pregnancy tumor of the gingiva (i.e., the granuloma gravidarum or pregnancy epulis) is a pyogenic granuloma that may appear in the second or third trimester and resolves shortly after delivery.

General Features Of The Skin

COLOR Skin color represents an aggregate of the remitted and reflected light, the wavelengths of which depend largely on the presence of four biochromes. Two biochromes are in the epidermis: melanin , which is brown and has a broad absorption in the ultraviolet and visible light ranges, and carotenoids, which are yellow. Two other biochromes are in the dermis: oxyhemoglobin, which is bright red and is found largely in the arterioles and capillaries of the papillary layer, and reduced hemoglobin, which is bluish red and is found in the subpapillary venous plexus. The dermal connective tissue may also contribute to the “whiteness” of the skin in lightly pigmented persons. 

General Features of the Hair and Nails

The distribution of the body hair, its texture, and amount should be noted as a part of the initial overall survey of the patient's skin, as should examination of the nails. The nails  can provide evidence of latent skin disease (psoriasis, lichen planus, alopecia areata, congenital ectodermal defect), as well as suggest the presence of renal or liver disease. Beau's lines (transverse indentations of the nails) and other variations on the theme of transverse white lines across the nails may be associated with a recent febrile or systemic illness, especially a renal or hepatic one. Telangiectasia in the periungual skin is a frequent and important diagnostic finding in systemic lupus erythematosus and dermatomyositis. 

General Features of the Mucous Membranes 

The initial general assessment of the patient must also include the oral, genital, and anal regions. The oral mucous membranes indicate the state of hydration and show pigmentary changes that can be racial traits or that may be helpful in the diagnosis of Peutz-Jeghers syndrome and Addison's disease. Among the many skin diseases that have mucous membrane manifestations are lichen planus, pemphigus, pemphigoid, herpes simplex, and erythema multiforme. The tongue may be red and smooth in various states of vitamin B deficiency. Soreness, as well as a beefy-red tongue, may be present as an initial complaint in pernicious anemia. The so-called black hairy tongue may be present as a relatively trivial problem, consisting of darkened, elongate filiform papillae that appear after the use of orally administered antibiotics or without any antecedent cause. The so-called geographic tongue consists of an irregular pattern of areas exhibiting absence of papillae; it may be associated with pustular and other varieties of psoriasis or it may be idiopathic. Lichen planus may be found on the tongue as linear white markings, sometimes in a netlike pattern. Oral thrush (moniliasis) occurs in diseases of altered immunity. Generalized monilial infections involving axillary, oral, periungual, and vaginal areas occur in the syndrome of mucocutaneous candidiasis and the syndrome of Addison's disease with hypoparathyroidism. Oral hairy leukoplakia occurs in HIV infection, often as an early sign.

EXAMINATION OF THE SKIN, HAIR, NAILS, AND MUCOUS MEMBRANES

EXAMINATION OF THE SKIN, HAIR, NAILS, AND MUCOUS MEMBRANES

The skin functions as a sensory organ; as an organ of metabolism that has synthesizing, excretory, and absorptive functions; as a protective barrier against the external environment; and as an important factor in temperature regulation. The clinical examination of the skin is partly an appraisal of these particular functions. In addition, however, the skin is synergistic with internal organ systems, and therefore, it reflects pathologic processes that are either primary elsewhere or shared in common with other tissues. The history of medicine suggests that diseases initially characterized as solely cutaneous (e.g., lupus erythematosus, dermatitis herpetiformis, and urticaria pigmentosa) have often subsequently been found to involve several systems.

In as much as visual appreciation of skin lesions is the sine qua non of dermatologic diagnosis, the examiner's eye is undoubtedly the most important instrument at his or her disposal. Yet the standardization of this instrument is a subject that receives scant attention, even though there are surprising variations in physicians' reports of what has been seen.

Furthermore, variability persists at every step of the diagnostic process, from description to differential diagnosis. The chances for correct recognition improve, of course, as the examiner gains familiarity with the various disorders of the skin. Even with experience, however, the greatest difficulty in diagnosis is often because of a failure to notice pertinent details from the available evidence.

Feinstein has challenged the tendency to favor laboratory tests that give numerical values as opposed to clinical observations. He wrote that clinicians try to be scientific in the use of inanimate objects but not in the use of their own sensory organs and brain. They often believe that their own human equipment is a hindrance instead of an advantage, an apology rather than an incentive for science in clinical work. Feinstein emphasized the need for more attention to sick people and the human methods of evaluating them, not to inanimate technology. Furthermore, the ability to arrive at a diagnosis through the history and physical examination is probably the most ancient, perhaps defining, and often—from an intellectual point of view—most satisfying attribute of being a physician. Physical diagnosis is an art, but no less a science because of it, and nowhere is the skill of physical examination more crucial to accurate diagnosis than it is in dermatology.

The examination of the skin should be made in a well-lighted room with natural light, if possible, or a “daylight” type of lamp. When feasible, the patient should be gowned, and examined completely and systematically in sections or quadrants. Articles of clothing are hindrances during the examination and may even be responsible for the inadvertent concealment of large areas of the skin.

The examination should commence with a general assessment of the patient as a whole—a “low-power” scan of the skin surface, during which rapid stock is taken of the skin, nails, and mucous membranes. The survey should include an appreciation of the color, moisture, the turgor, odor and the texture of the skin. Clothing may give clues to the cause of a suspected contact dermatitis or parasitic infestation (e.g., pediculosis).

Efflorescence Of Skin Disorder

Efflorescence is defined as lesion on skin which are visible for naked eyes and possible for palpation during examination. Efflorescence is divided in two types : primary Lesions and seccondary lesion. Primary lesion, when the lesion appear at the beginning of the disease. Secondary lesion, when the lesion appear as the disease progresses.

Primary Lesions

Descriptions of the basic primary lesions follow:

Macules are up to 1 cm and are circumscribed, flat discolorations of the skin without any elevation or depression. Examples: flat nevi, freckles. Patches are larger than 1 cm and are circumscribed, flat discolorations of the skin. Examples: senile freckles, vitiligo, measles rash.

Papules are up to 1 cm and are circumscribed, elevated, superficial, solid lesions. Examples: warts, elevated nevi, lichen planus. A wheal is a type of papule that is edematous and transitory (present less than 24 hours). Examples: Hives, sometimes insect bites.Plaques are larger than 1 cm and are circumscribed, superficial, elevated,solid lesions. Examples: lichen simplex chronicus,mycosis fungoides.

Nodules range to 1 cm and are solid lesions with depth; they may be above, level with, or beneath the skin surface. Examples: nodular secondary or tertiary syphilis, xanthomas, basal cell cancers. Tumors are larger than 1 cm and are solid lesions with depth; they may be above, level with, or beneath the skin surface. It is a common term to describe any non algnant or malignant mass. Examples: larger basal cell cancers,  tumor stage of mycosis fungoides.

Vesicles range to 1 cm and are circumscribed elevations of the skin containing serous fluid. It forms erosion when rupture  and join with the likes to form bulla. Examples:  herpes zoster, early chickenpox, contact dermatitis.

Bullae are larger than 1 cm and are circumscribed elevations containing serous fluid. Examples: second-degree burns, pemphigus,.

Pustules  is similar to vesicle except that it is filled with pus.   vary in size and are circumscribed elevations of the skin containing purulent fluid. It appears on inflammatory skin. Examples: acne, impetigo.

Petechiae range to 1 cm and are circumscribed deposits of blood or blood pigments. Examples: thrombocytopenia ,dengue fever and drug eruptions.

Purpura is a larger than 1 cm circumscribed deposit of blood or blood pigment in the skin. Examples: senile purpura and vasculitis.

Urticaria , a flat elevation of skin due to edema of upper dermis. It is characterized by itches, rapid onset, rapid resolution, widened pores and pallor.

Secondary Lesions

Secondary lesions include the following:

Scales are shedding, dead epidermal cells that may be dry or greasy. Examples: dandruff (greasy), psoriasis (dry).

Crusts are variously colored masses of skin exudates. Examples: impetigo, infected dermatitis.

Excoriations are abrasions of the skin, usually superficial and traumatic. Examples: scratched insect bites, scabies.

Fissures are linear breaks in the skin, sharply defined with abrupt walls. Examples: congenital syphilis, athlete's foot.

Ulcers are irregularly sized and shaped excavations in the skin extending into the dermis or deeper. Examples: stasis ulcers of legs, tertiary syphilis.

Scars are formations of connective tissue replacing tissue lost through injury or disease. Keloids are hypertrophic scars beyond the borders of the original injury.

Lichenification is a diffuse area of thickening and scaling with resultant increase in the skin lines and markings.

Several combinations of primary and secondary lesions commonly exist on the same patient. Examples: papulosquamous lesions of psoriasis, vesiculopustular lesions in contact dermatitis, and crusted excoriations in scabies.

Special Lesions

Some primary lesions, limited to a few skin diseases, can be called specialized lesions.

Comedones or blackheads are plugs of whitish or blackish sebaceous and keratinous material lodged in the pilosebaceous follicle, usually seen on the face, the chest, or the back, rarely on the upper part of the arms. Example: acne.

Milia are whitish nodules, 1 to 2 mm in diameter, that have no visible opening onto the skin surface. Examples: in healed burn or superficial traumatic sites, healed bullous disease sites, or newborns.

Telangiectasias are dilated superficial blood vessels. Examples: spider hemangiomas, chronic radiodermatitis.

Burrows are very small and short (in scabies) or tortuous and long (in creeping eruption) tunnels in the epidermis.

In addition, distinct and often diagnostic changes in the nail plates and the hairs are discussed in the chapters relating to these appendages.