INTRODUCTION

A detailed physical examination (status) and precise history (anamnesis) are the first and essential steps of correctly diagnosing skin-related conditions [1]. The practice of these clinical skills should be a core component of the medical curriculum but unfortunately, they often do not receive sufficient attention, neither educational resources [2,3]. The aim of this article is to describe the process of physical examination and history taking typical to skin conditions in a step-wise manner. Studies or pedagogical research on the topic are largely missing in the literature [4,5] and therefore the article has the form of an essay from an experienced teacher to a novice doctor.

During the patient encounter, visual assessment of the skin is the most important part of the consultation, and its role must not be underestimated. Based on observed findings, a clinical working diagnosis is made and subsequently either confirmed or rejected in the light of context and differential diagnoses (Fig. 1). At an early stage of the consultation, one should move to the physical examination, as it plays the key role in evaluating the need and extent of further investigations.

Figure 1: Schematic picture of the diagnostic process and clinical reasoning in patients with skin conditions. Based on the information obtained in the physical examination and past history, a clinical working diagnosis is made and subsequently either confirmed or rejected in the light of possible differential diagnoses. The working diagnosis is continually evaluated, and differential diagnoses are ruled out by asking targeted questions, looking for further clinical findings or by carrying out further investigations (e.g., histology).

Initially, the patient may be asked some short general questions during the physical examination. Afterwards, a more comprehensive interview related to the present skin condition and the patient’s background should be conducted. It is important that all of the patient’s skin findings are noted clearly and factually, and conclusions are not drawn too quickly. The extent of the physical examination depends on the situation and the skin condition [6]. Especially in cases of diagnostic challenges a systematic approach involving all skin areas and the mucous membranes cannot be emphasized too much [7].

THE PHYSICAL EXAMINATION (STATUS)

Enough time should be ensured for carrying out the physical examination. Visual assessment is best performed in good illumination, systematically and calmly [8]. The order in which different body sites are examined depends on the examiner, the patient and characteristics of the skin condition [9]. It typically involves inspection of the whole skin, mucous membranes, hairs and nails. Many experienced dermatologists start with the hands and upper limbs, then move on to the face, upper body, back, neck, scalp, and the head. Subsequently, they follow the examination of the lower back, sacrum, lower limbs, and legs. Finally, if necessary, the mucous membranes of the mouth, genital and gluteal areas are assessed. It is also important not to forget to examine the nails, skin on the palms and soles (palmoplantar areas), the scalp, the back of the ears, the armpits, and interdigital spaces. Important diagnostic clues may often be found in hidden body sites.

The initial phase of the examination aims to get a clear picture of the patient’s general condition. Observing the patient’s behavior will provide valuable information about the state of mind and disease burden. The main aim is to detect pathological changes in the skin [10]. Thus, any lesions should be recorded purely on the basis of what is actually seen, rather than rushing to interpret their significance. The dermatological diagnosis is not based only on isolated observations but is rather a synthesis of multiple findings to create an overall concept [11]. Reversing one’s own working diagnosis when new, contradictory findings emerge is difficult and requires an open mind and practice [12]. It is important that the skin lesions are expressed in clear terms, since their description is essential in the process of clinical reasoning [13,14].

It is often worth considering the simplest observations, which are generally very important. For example, shingles appear on only one side of the body in the area of a nerve segment (dermatome). Many intrinsic skin conditions (e.g., atopic dermatitis, Fig. 2b) occur quite symmetrically on both sides, while extrinsic conditions (e.g., skin infections such as tinea, Fig. 2c) are usually concentrated only on one side, i.e., unilateral. After acquiring a general picture, one proceeds to the assessment of individual skin lesions. Efforts should be made to identify which skin lesions are present (primary and secondary lesions, Fig. 3) and where they are located. It is relevant to discriminate whether they are concentrated on typical sites of skin diseases (predilection sites) or how they can be explained otherwise.

Figure 2: The figure shows typical secondary skin lesions. It is also important to note the different shapes and forms (configuration), body sites (predilection sites) and distribution. a) Sharply demarcated red plaques with thick white, flake-like scales. Symmetric distribution on both extensor surfaces of the elbows. Psoriasis. b) Whitish hyperpigmented patches and thickening of the skin with punctate superficial erosions (excoriations) due to scratching. Skin lesions are symmetrical and in both flexural folds of the knees. The lines of cleavage are clearly visible and prominent (lichenification). Chronic atopic dermatitis. c) Round, sharply demarcated, red plaques with a ring shape. Fine scaling is concentrated on the outer edges of the ring. Tinea corporis. d) Sharply demarcated, oval, red macules with a fine scaling on the outer edge (collarette). The past history reveals a two-stage disease course: the biggest macule (herald patch) appears first, and multiple smaller ones appear within some weeks. Pityriasis rosea. e) Testing dermographism in a patient with chronic urticaria. Scratching the back area with, e.g., a wooden tongue depressor. After some minutes linear wheals with a red border appear on the scratching sites. Dermographism. f) Diascopy of a patient’s skin with cutaneous sarcoidosis. A patchy, dark yellow color resembling apple jam (infiltrate) is seen after pressing the skin vertically with a transparent object.

Figure 3: The figure shows examples of typical primary lesions. It is also important to note their different colors, shapes and forms (configuration) and their arrangement (relationship of individual skin lesions with each other). a) Red elevated wheals with no scaling, erosions or other secondary lesions. Urticaria. Some brown, oval-shaped seborrheic keratoses are also visible. b) Localized red-bluish papules are seen in the shin and ancle area. The surface of the papules has a white net-like appearance. Lichen planus. c) A solitary black nodule beneath the ear with an asymmetric structure and texture. The histology confirmed the diagnosis of a melanoma. d) Poorly circumscribed red macules, small red papules and clear small vesicles. Acute dermatitis. e) Large, clear, yellowish bullae on red macules on a patient’s flank. Bullous pemphigoid. f) Yellowish vesicles and pustules on red macules. Grouped together in the palm area. Herpes simplex.

In most cases, answers are sought to straightforward questions regarding visual information (Table 1). What lesions are seen in the patient’s skin? Where are the skin lesions located? How many lesions are visible and how are they distributed (e.g., single or widespread changes)? Are there specific lesions (e.g., comedones in acne)? What shape are they (e.g., round or linear)? What is the color of the lesions (e.g., bluish-pink papules in lichen planus, Fig. 3b)? Are all lesions the same? Do you see lesions in different stages of development (e.g., different stages of pustules in palmoplantar pustulosis)? Do the lesions leave marks or scars as they heal?

Table 1: Important components of the physical examination (status) and patient history (anamnesis) in patients with skin conditions. Practical examples.

Usually, skin lesions are not randomly located, so their site plays a key role in the diagnosis (Table 2) [7,15]. Skin diseases have their own typical body sites (predilection sites), e.g. in psoriasis the extensor surfaces of the limbs (Fig. 2a) and the scalp, or in atopic dermatitis the elbow and knee folds (Fig. 2b), face and neck. Individual skin lesions should also be assessed at close range (magnifying lens distance) so that their form, demarcation, surface, and texture can be analyzed. For example, pityriasis rosea shows sharply bordered reddish patches which are usually oval in shape (Fig. 2d) with a collar-like scaling on the edge (collarette).

Table 2: Examples of common localization of skin diseases (predilection sites), shapes and forms of skin lesions (configuration) and different patterns of distribution.

Finally, all findings are interpreted in the light of the patient’s overall picture and the clinical situation (context). In the majority of cases, this will allow a working diagnosis to be formulated. It is then important to consider differential diagnoses, i.e. skin conditions with visual patterns that appear similar [16]. The working diagnosis is self-critically evaluated, and differential diagnoses are ruled out by asking targeted questions, looking for further clinical findings or by carrying out further investigations (e.g. microscopy of tissue samples, laboratory or microbiological tests, Fig. 1) [17].

OTHER STATUS FINDINGS

Physical examination is often accompanied by palpation and further status findings with the help of easily available aids. Palpation is used to investigate the texture, surface, and mobility of the skin lesion on its base [18,19]. It is particularly important when assessing solitary lesions and tumors (Fig. 3c). Using the back of the hand, the temperature can be felt and compared to the contralateral body site. For example, in erysipelas the skin surface feels warm.

The surface and scaling of lesions can be assessed by gently scraping them with a wooden tongue depressor (spatula). For example, in tinea, the scaling is concentrated around the edges of reddish patches (Fig. 2c). A blunt object can be used to assess the presence of dermographism on the upper back, suggestive of urticaria (Fig. 2e). In diascopy, the skin is pressed with a transparent object (e.g., glass slide) to assess its composition. In the case of small punctate bleedings (purpura), individual petechiae do not fade with pressure. In some granulomatous skin diseases, e.g. sarcoidosis, a dark yellow color resembling apple jam (infiltrate) is seen in the diascopy (Fig. 2f).

Dermoscopy may also be used to assess individual lesions. It is based on microscopy of the skin surface at a ten times magnification. In many skin tumors, characteristic structures can be seen and diagnostic accuracy increased. For example, seborrheic keratosis can usually be easily distinguished from melanoma (Fig. 3c). It is a routine tool for dermatologists, but its use is increasing in primary care and other specialties. It can also be of considerable help in many other skin conditions, such as the detection of scabies mites or the differential diagnosis of inflammatory skin diseases.

APPEARANCE AND SHAPE OF SKIN LESIONS

An important step of the physical examination is the assessment of the appearance of skin lesions (morphology) [20]. Individual changes (efflorescences) can be divided into primary and secondary lesions (Fig. 3d and Fig. 2a). The International League of Dermatological Societies have revised and published a glossary for the description of cutaneous lesions [21]. Identification of skin lesions helps to make the correct diagnosis, and the precise use of descriptive terms also clarifies communication [22,23].

Primary lesions appear on healthy skin at early stages of the disease, such as red macules, vesicles (Fig. 3d), and papules in acute dermatitis. As the disease progresses, they are often more easily found at the edge of larger, fused lesions. Secondary lesions develop after the primary ones. In chronic atopic dermatitis, for example, scaling and lichenification may develop (Fig. 2b). There are often many different lesions visible comprising a mixed clinical picture. It is therefore important to assess whether the skin lesions are in the same developmental stages as, for example, in herpes simplex (Fig. 3f) or whether different stages are seen together (e.g., in palmoplantar pustulosis). Scaling, blistering (Fig. 3e), or erosions are signs of superficial changes in the epidermis. If the skin condition is only present in deeper structures, e.g. the dermis, the surface is usually intact, the lesions are less sharply demarcated and have a smooth surface on palpation (e.g., urticaria, Fig. 3a, or erythema nodosum) [24].

The lesions’ individual shape (configuration), demarcation, texture and colors may also provide very useful information (Table 2) [25]. In tinea, for example, the typical lesion has an annular configuration (round lesion with central clearing) (Fig 3c). Other examples are serpiginous lesions which show a snake like winding shape such as in cutaneous larva migrans. In many cases, it is worth paying attention to the surface (topography) and color shades of the changes [26]. For example, in lichen planus, red papules typically show a bluish-pink color (Fig. 3b) with white reticular surface structures (Wickham’s lines). Skin lesions appear differently in darker skin (Fig 2b) and therefore also the patients’ skin type (Fitzpatrick type) has to be considered [27].

THE PATIENT HISTORY (ANAMNESIS)

After the physical examination, the next essential part of the patient consultation is the patient history. A large proportion of skin diseases are diagnosed clinically by comparing the current findings with verbal information (Table 1). Therefore, it is important to focus on a detailed patient interview which usually has two main aspects, the skin condition itself and the patient’s background [20,21].

The chronology of the skin condition itself can be divided into two phases. First, the development and dynamics of the skin condition (entity) and, second, its causes (etiology) [1,24]. Patient history requires good imagination skills to outline the time of onset, the temporal dynamics of the lesions, the initial findings, and their location. Often previous photographs are crucial. The single most important question relates to the duration. In acute skin conditions, the emphasis is on possible causal links to external factors.

The parts of the interview regarding etiology concentrate on the triggering or aggravating factors that contributed to the skin condition before it started. When assessing the temporal relationship between cause and effect, it is often useful to use an illustrative desk calendar or timeline. For example, drug-induced rashes typically occur within a 7–10-day time window from the start of the causative drug [28].

Symptoms give important clues about the underlying condition [20]. It is important to evaluate changes in general condition, fever or other constitutional symptoms, and if the lesions have a temporal link to infections or drugs. Itching is typically associated with skin diseases (e.g., atopic dermatitis, hives) while pain is typically caused by skin infections (e.g., shingles, boil). Asymptomatic lesions may be caused by reactive skin diseases (e.g., erythema multiforme) or autoimmune diseases.

One should always ask the patient about previous treatments. The appearance of the skin lesions may change with treatment and thus masquerade the initial clinical picture. A good example is the transformation of ringworm (Fig. 2c) into tinea incognita when treated with high-potency topical corticosteroids [17]. Assessing the response to treatment also gives information about the condition (e.g. dermatitis usually has a good response to topical corticosteroids). Previous treatments can also be used to identify triggering factors, including contact allergies.

The mnemonic of the three cutaneous C’s includes the most important questions when interviewing patients with skin conditions: 1. Course (duration and dynamics), 2. complaints (symptoms), and 3. creams (previous treatments and their responses) [29].

Other relevant background information includes the general health and history of skin disease, other diseases, medication, family history of skin disease, allergies, and atopic predisposition. Occupation (especially in hand dermatitis), leisure irritants, travel and skin conditions in close contacts are also important.

CONCLUSIONS

The physical examination and patient history should be carried out consistently and accurately. They do not consist merely of observing and listing open questions but are conducted in a thorough and systematic manner [30]. Essential questions are asked in all patients [31]. Based on the findings and answers received, further targeted questions and visual findings are actively addressed and searched for according to the condition and the context.

A well-conducted physical examination and past history strengthen the patient-physician relationship and have a positive impact on the treatment success [32]. They also contribute to the fact that the patient feels examined and listened to, i.e. they are already part of the treatment. Every doctor should practice and maintain clinical skills, as they encapsulate the core principles of medicine, i.e., the patient encounter, the physical examination and clinical reasoning [33,34].

In terms of cost-effectiveness, eyes and ears are the best tools of the physician, and the continuous development of clinical skills also increases the meaningfulness and motivation of clinical work. Genuine interest, objective observation, and healthy skepticism towards one’s own or others’ conclusions ensure the path to a correct diagnosis. Physical examination and history taking are best carried out on the basis of these principles. Be a bedside Sherlock Holmes [35]!