Differential diagnosis

The differential diagnosis for PIH includes the following fixed drug eruption, systemic drug-induced hyperpigmentation, macular amyloid, ashy dermatosis, melasma, and tinea versicolor. Medications such as tetracyclines, antimalarial drugs, arsenic, bleomycin, and doxorubicin can result in hyperpigmentation of the skin. 

The diagnosis of PIH is often made by history and clinical presentation. It is characterized by macules and patches of varying shades of hyperpigmentation limited to the sites of inflamed skin lesions. Lesions of the preceding inflammatory process may be present at vari- 

Acne is rarely misdiagnosed. Occasionally, however, there is ambiguity. The term acnei- 

Rosacea is a chronic disorder affecting the central parts of the face, characterized by flushing, persistent erythema and teleangectasia. Inflammatory papules and pustules can develop within the areas of erythema. Rosacea typically occurs in adults with fair skin and light eye and hair color. In contrast to acne, rosacea is not typically follicular in nature and comedones and seborrhea are usually absent. Pyoderma fa-dale is deemed to be an explosive form of rosacea, often occurring in young women with a phenotype typical of rosacea patients, often in the context of stress (Fig. 11.16). 

Perioral dermatitis is characterized by erythema, scaling and small papules and pustules symmetrically distributed around the mouth, sometimes extending to the nasolabial folds and the cheeks. This condition typically occurs in females 20-40 years of age. Topical corticosteroids can exacerbate the disease and should be avoided. 

Folliculitis caused by colonization with S. aureus or S. epidermidis on the face can be sometimes misdiagnosed as acne. The prominent lesions are superficial follicular pustules that are often distributed on the lateral cheeks, the chin and the temporal sites of the forehead. The rare folliculitis due to Candida may also present as multiple pustular eruptions. 

Topical retinoids acting on gene transcription regulate cell proliferation and differentia- 

The following factors have been suggested as alternatives to consider when presented with a potential case of exposure to nerve agents carbamate and organophosphate pesticides alkaloids such as nicotine or coniine ingestion of mushrooms containing muscarine and 

A casualty with symptoms in two or more organ systems (not including miosis or rhinorrhea), who has a heartbeat and a palpable blood pressure. The casualty may or may not be conscious and/or breathing. 

A casualty with a known expossure to a solid agent or solution but no apparent signs or symptoms, or a casualty who is recovering from a severe exposure after receiving treatment. 

A casualty who is walking and talking, although miosis and/or rhinorrhea may be present. 

A casualty who is not breathing and does not have a heartbeat or palpable blood pressure. 

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Fohc acid is a precursor of several important enzyme cofactors required for the synthesis of nucleic acids (qv) and the metaboHsm of certain amino acids. Fohc acid deficiency results in an inabiUty to produce deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and certain proteins (qv). Megaloblastic anemia is a common symptom of folate deficiency owing to rapid red blood cell turnover and the high metaboHc requirement of hematopoietic tissue. One of the clinical signs of acute folate deficiency includes a red and painhil tongue. Vitamin B 2 folate share a common metaboHc pathway, the methionine synthase reaction. Therefore a differential diagnosis is required to measure foHc acid deficiency because both foHc acid and vitamin B 2 deficiency cause... 

This form of myositis stands apart from the classical PM/DM syndromes on account of its distinctive clinical and histopathological features. There is no clear difference in incidence between males and females and the disorder is typically one of middle or old age. In the majority of cases, progression is slow and skin involvement is not seen, so that the main question of differential diagnosis is its distinction from chronic PM. Unlike classic PM, weakness involves distal muscles as frequently as proximal muscles. CK levels are usually only moderately raised. A common finding which leads to the correct diagnosis of this condition is its nonresponsiveness to steroid treatment or other forms of immunosuppression. 

Medications that have been used as treatment for anxiety and depression in the postwithdrawal state include antidepressants, benzodia2epines and other anxiolytics, antipsychotics, and lithium. In general, the indications for use of these medications in alcoholic patients are similar to those for use in nonalcoholic patients with psychiatric illness. However, following careful differential diagnosis, the choice of medications should take into account the increased potential for adverse effects when the medications are prescribed to alcoholic patients. For example, adverse effects can result from pharmacodynamic interactions with medical disorders commonly present in alcoholic patients, as well as from pharmacokinetic interactions with medications prescribed to treat these disorders (Sullivan and O Connor 2004). 

Table 4. Differential diagnosis of anaphylactic reactions (according to Przybilla)... 

Hematology and clinical chemistry should be considered in more severe exanthema, as systemic involvement has been described [1]. A skin biopsy may sometimes be needed for differential diagnosis. 

The porphyrias are a group of disorders due to abnormalities in the pathway of biosynthesis of heme they can be genetic or acquired. They are not prevalent, but it is important to consider them in certain circumstances (eg, in the differential diagnosis of abdominal... 

Not needed for differential diagnosis of acid-base hibalamce. j " NVH (Non-ventilatory hypoxia) P.02 norhal but PyOa abnormal. 

Differential Diagnosis of Acid-Base Equilibrium. POg values are arterial From Welsberg ( ). 

Differential Diagnosis of Acld Base Equlllbrli3m PO values are arterial. From Welsberg (1 ). 

HBD is a biochemical rather than electrophoretic assessment of the LD isoenzyme which is associated with heart. All five isoenzymes of LD exhibit some activity toward cx-hydroxy-butyrate as substrate, but heart LD shows the greatest activity. Serum HBD measurement is not as valuable as the electrophoretic determination of heart LD isoenzyme. High HBD activity has also been found in diseases of the liver. Rises associated with the hepatic effects of congestive heart failure can be disconcerting in the differential diagnosis of myocardial infarction. Wilkinson has used the serum HBD/LD ratio for the differentiation of myocardial disease from other disorders in which HBD activity is elevated, whereas Rosalki has not found the ratio to be helpful (39). 

While considerable amounts of both GOT and GPT are found in cardiac muscle, skeletal muscle and kidney, differential diagnosis is aided by the fact that the liver shows a much higher total GPT activity. An important clinical application of measurements of transaminase activity is the detection and diagnosis of viral... 

Amantuni, V.G. and Saiarian, M.D. (1986a). Metabolic aspects of the differential diagnosis of chronic asthmatic bronchitis and bronchial asthma. Ter. Arkh. 58, 12-14. 

All of the tests described for acute diarrhea would be used to establish a diagnosis of chronic diarrhea because the differential diagnosis is more complicated. The data obtained can help categorize the diarrhea as watery, inflammatory, or fatty, narrowing the focus on a primary disorder. 

Metabolic acidosis is characterized by a decrease in serum HC03. The anion gap is used to narrow the differential diagnosis, as this acidosis may be caused by addition of acids (increased anion gap) or loss of HC03 (normal anion gap). The compensation for metabolic acidosis is an increase in ventilation with a decrease in arterial C02. 

The excess gap represents the amount of HC03 that has been lost due to buffering unmeasured cations. The excess gap can be added back to the measured HC03 to determine what the patient s bicarbonate would be if these endogenous acids were not present. This is a very valuable tool that can be used in narrowing the differential diagnosis of certain acid-base disorders as well as in uncovering occult or mixed acid-base disorders. 

Visceral pain involves injury to nerves on internal organs (e.g., intestines or liver) and can present as diffuse, poorly differentiated, and often referred pain. Acute pain should be treated aggressively, even before the diagnosis is established, except in conditions of head or abdominal injury where pain may assist in the differential diagnosis. 

Other diagnostic tests to consider for differential diagnosis erythrocyte sedimentation rate, urinalysis, toxicology, chest x-ray, heavy metal screen, HIV testing, cerebrospinal fluid (CSF) examination, electroencephalography, and neuropsychological tests such as the Folstein Mini Mental Status Exam. 

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