Eye diagnosis: skin signs of internal diseasesThe clinical examination is considered by many doctors as a discontinued model: the whole palpation, auscultation and inspection costs only time – and besides, there are the apparative diagnostics, which are anyway more reliable. The inspection can provide findings that can be decisive for the further procedure. The experienced diagnostician Prof. Dr. med. Hermann Fuebl explains the most important dermal signs of internal ailments.
Once upon a time, many years ago, the clinical examination was the most important means of medical diagnosis. Today, doctors use their eyes and hands primarily to operate personal computers, and the stethoscope serves many only as a status symbol. This goes so far that some colleagues almost completely abandon the findings of the physical examination. A true diagnostic panopticon opens up for the connoisseur, if he knows how to interpret these signs correctly. Above all the skin offers a multiplicity of findings, which are sometimes nearly pathognomonic – in many cases however at least pointing the way – for internal diseases. Many clinical examination methods are inferior to apparative diagnostic methods in sensitivity and specificity though. However, they have invaluable advantages that go far beyond their immediate value as a diagnostic tool. Among other things, the physical examination of the patient is virtually free of side effects, cheap and can be repeated as often as desired. Above all, however, most patients perceive it as a sign of the doctor's dedicated attention, the likes of which can hardly be conveyed with a device. Sometimes patients are amazed at the diagnostic conclusions that can be drawn from careful inspection of the skin alone. This reaction facilitates further therapy. Serves – not least – your reputation as a doctor.
Gaze-diagnostic "color theory
When examining a patient, one of the most obvious features to look for is the color of the skin. This can vary extremely, depending on many individual, external and vegetative factors. Nevertheless, there are some changes in skin color that allow diagnostic conclusions to be drawn. In case of pronounced anemia (Hb 7-8 g/dl), there is z. B. to a waxy pallor of the skin. You can get an impression unadulterated by skin pigment by pulling down the lower eyelids a little and looking at the conjunctivae. Also, look for the color of the nail bed (s. Fig) and the palms. When in doubt, use your own hand for comparison. If you see petechiae or an unusual number of hematomas in parallel with the pallor, this could be indicative of a hemorrhagic diathesis and suggest thrombocytopenia or leukemia.
If the skin discolors blue, there are often harmless neurovegetative mechanisms behind it – usually triggered by cold air. When the skin warms up again, this discoloration largely disappears. If the blue discoloration persists, however, it may also indicate a serious disturbance of the oxygen supply to the blood in the sense of cyanosis (s. Fig.). From a level of 5 g/dl of deoxygenated hemoglobin, the trained diagnostician can clinically recognize cyanosis. A distinction is made between peripheral and central cyanosis, which may also be present simultaneously. In the first case, the blood flow in the periphery of the body is so slow that there is a disproportion between oxygenated and deoxygenated hemoglobin (exhaustion cyanosis). In the latter case, there is an unphysiological mixture between oxygen-rich. Oxygen-deficient blood due to a shunt vitium in the heart or insufficient oxygenation of the blood in the lungs (mixed cyanosis). Clinically, you can distinguish peripheral from central cyanosis by inspecting the tongue. In peripheral cyanosis the tongue color usually remains normal, in central cyanosis the tongue is also bluish discolored.
If the entire skin is discolored yellow due to elevated bilirubin, this is called icterus. The phenomenon is usually seen above a serum bilirubin level of 2-2.5 mg/dl. Yellow discoloration is first noticed in the conjunctiva. This membrane is transparent. Is located in front of the white sclera (s. Fig.). This is why it is often mistakenly referred to as sclerenic terus. However, it is not the sclera itself but the conjunctiva that first turns yellow in jaundice. If you want to assess jaundice, it is important that you inspect the patient in daylight if possible, as artificial light, especially fluorescent light, makes it much more difficult to see yellowing. This is also the reason why patients often notice jaundice only after other people have pointed it out to them, despite looking in the mirror every day. Icterus is always a worrying symptom. It can be prehepatic (z. B. due to hemolysis), intrahepatic (z. B. in hepatitis or liver cirrhosis) or posthepatic (z. B. may be due to obstruction of the hepatocholedochal duct).
This young patient with acute hepatitis B in drug abuse shows marked conjunctival icterus (bilirubin 5.3 mg/dl).
The lower hand belongs to a 56-year-old with severe chronic obstructive pulmonary disease (COPD), the upper hand to a healthy person. Comparison shows the cyanotic blue coloration of the patient with lung disease.
This 73-year-old patient with heart failure shows cyanosis of the acras (chin, nose, cheeks). There the increased exhaustion. The insufficient oxygenation of the blood especially clear from.
Fingertips of a patient with tumor anemia (Hb 7.3 g/dl). The anemia can be recognized by the pale nail beds.
Metabolism for the eye
Other disease patterns, some of which manifest themselves pathognomonically on the skin, include metabolic disorders. Changes in lipid, glucose, uric acid and pophyrin metabolism are the main skin signs. In the case of lipid metabolism disorders, the distribution pattern can be used to determine. Drawing conclusions from the nature of the deposits as to their cause. Thus, tuberous xanthomas are predominantly found in familial hypercholesterolemia (s. Fig), located mainly over strong tendons, and xanthelasma around the eyelids (s. Fig). To avoid overlooking tendon xanthomas, you should examine the Achilles tendon, patellar tendon, and triceps tendon very closely. Eruptive xanthomas (s. Fig.) are typical for hyperlipoproteinemia type III, hand line xanthomas for type IV.
Diabetes mellitus also favors a whole series of skin manifestations. These include z. B. intertriginous mycoses and other infections. However, these are not specific. Therefore diagnostically not very helpful. An exception is necrobiosis lipoidica, a rare granulomatous inflammation occurring in about 0.3% of all diabetics, in which lipids accumulate in the middle dermis (s. Fig). Women are more frequently affected than men. The inflammatory lesions can be the size of a palm. In about one third of cases, poorly healing ulcerations develop.
Hyperuricemia that has been present for many years can also first be seen on the skin. In this disease, whitish uric acid deposits can occur in bradytrophic ties such as tendons, cartilage and bone. Typically, these so-called tophi are found in the region of the auricular cartilage (s. Fig.). Gouty pearls" can also form on the joint capsules of the finger joints, on flexor and extensor tendons, on the nasal cartilage and in the skin. These can lead to deformities of the fingers. If one of these "pearls" is opened with a scalpel, whitish friable material is discharged: pure urate. The most frequent disorder of porphyrin metabolism in our latitudes is porphyria cutanea tarda. It occurs in as many as 1% of the population between the ages of 40 and 30. and 70. At the age of. There is an association with mostly alcohol toxicity-related liver damage. On the chronically light-exposed skin areas, especially on the dorsum of the hand, there are juxtaposed fresh erosions, blisters, hemorrhagic-crusted lesions, and hyperpigmented scars (s. Fig.). This is a visual diagnosis, which is confirmed by the detection of an increased concentration of porphyrin in the urine. This appears beer-brown but fluoresces reddish in Wood's light (UV light). The various porphyrins can be quantitatively determined in 24-h urine.
The elbows of this 57-year-old patient show tuberous xanthomas. These speak for a hypercholesterolemia type IIb according to Fredrickson. The patient complained of feeling thirsty. Had lost 5 kg in four weeks. Serum cholesterol. Triglycerides significantly elevated.
This patient with familial hypercholesterolemia shows xanthelasma on both eyelids .
A "gouty pearl" is clearly visible on this patient's ear. The 62-year-old had suffered from untreated hyperuricemia for years.
The nodules on the buttocks of this 45-year-old man are eruptive xanthomas secondary to hyper-triglyceridemia and diabetes. The patient's serum looked like milk, his triglyceride level was 1.300 mg/dl, the blood sugar at 380 mg/dl. The xanthomas consist of cutaneous deposits of macrophages that have phagocytosed chylomicrons.
The typical picture of necrobiosis lipoidica is seen on the lower leg of this 54-year-old woman with type 2 diabetes. Initially, red, lentil-sized papules form, which later sink below the level of the skin. Later they turn yellowish. Are permeated by telangiectasias.
The typical changes in Pophyria cutanea tarda: Characteristic is the colorful picture of different efflorescences existing side by side.
Organs in the "dermal mirror
If you look closely, you can also observe sometimes very characteristic changes in patients with organ damage. The prime example is liver cirrhosis. Typical are z. B. the palmar erythema and the "belly baldness" in men, in which a female pubic hair type develops. In addition, cirrhosis often manifests as gynecomastia, caput medusae indicating a bypass of the portal system, and the typical spider nevi (nevus araneus, s.Fig). These are arterial-capillary vascular neoplasms that may occur primarily in the anterior thoracic region, shoulders, and face. Unlike erythema, they fill from central to peripheral after finger squeezing because they are fed by a central arterial-capillary vessel. The cause of the "spider nevus" is unclear.
Another condition for which a look at the skin can be helpful is endocarditis. This diagnosis is often difficult to make. Even the supposedly obligatory symptom of fever may occasionally be absent, blood cultures are also unreliable, and echocardiographic evaluation of the heart valves is often difficult. In bacterial endocarditis, however, subungual splinter hemorrhages and Osler nodules may develop (s. Fig.). Probably caused by microemboli of valvular deposits in acral vessels or immune complex vasculitis. Osler nodules appear as small, reddish papules on the tips of the fingers and toes. Splinter hemorrhages are typically found under the fingernails.
Butterfly and hummingbirds
The diagnostic look at the skin is especially important in rare diseases. These are often recognized late, although they often manifest themselves with pathognomonic signs on the skin. An example are collagenoses. It is true that the rheumatologist rarely makes the final diagnosis of these diseases on the basis of skin findings alone. It can, however, help to order the groundbreaking laboratory chemical and instrumental examinations. Thus, a patient with butterfly erythema should be urgently clarified as to whether he or she has lupus erythematosus (s. Fig). Less common and easily overlooked at a cursory glance are the periorbital heliotrope erythema in dermatomyositis (s. Fig.) or nailfold hyperkeratosis in progressive systemic scleroderma (see Fig.). Disease. It is inherited in an autosomal dominant manner. Manifests on the skin with a typical combination of efflorescences. It is inherited in an autosomal dominant manner and manifests itself on the skin with a typical combination of efflorescences. If several coarse, non-prere-dole skin tumors (neurofibromas) and several milk-coffee-colored hyperpigmentations (cafe-au-lait spots) are found, this disease may be suspected (s. Fig). Patients may be less gifted or suffer from epilepsy. It is important to have the combination of both findings: Cafe-au-lait spots can occur in all people and are a completely harmless finding. Finally, a "hummingbird": occasionally, a peculiar tortuous venous pattern is found in the lower thoracic aperture in older men (s. Fig.). This phenomenon was first described in 1913 by the internist Hermann Sahli. He postulated that all men with the venous garland named after him had emphysema. The pathogenesis of this finding was discussed by Sahli. His colleagues at that time very lively. However, the reverse is not true. Only a fraction of men with emphysema develop this clinical sign. Is it then at all necessary to know the Sahli sign? Certainly, emphysema can be excellently diagnosed and treated even if one is not familiar with the venous ring described by Hermann Sahli. But also for the Sahli sign applies what is true for many skin signs of internal diseases: It does not only give additional certainty, it also gives you a deep feeling of satisfaction, diseases not only with laboratory values, x-rays& Co.