Erythema L53.91

• Circumscribed, differently sized, polyaetiological (exogenous or endogenous) solitary, sharply or blurredly limited, pale to deep red or bluish livid, normothermic or hyperthermal or, more rarely, hypothermic, red, anaemic spot. An erythema differs in colour, size, arrangement and presents itself as a contrast to the non reddened, bright surroundings and is only perceptible through this contrast. In the case of a universal redness, an erythroderma, the contrast to a normal environment is naturally missing.
• Furthermore, in principle, various clinical aspects must be taken into account and evaluated diagnostically when assessing a solitary erythema or multiple erythema. These are in particular:
  • Size
  • Number and distribution (solitary, multiple, grouped, disseminated, exanthematic, universal)
  • dynamics (static, acutely volatile, acutely persistent, chronically persistent, crescendo reaction with increasing dynamics, wave dynamics with increasing phase, plateau phase and decrescendo phase)
  • Arrangement and shape (gyriated, herpetiform, serpiginous, in Blaschko lines, segmental, anular, shooting target or cockade-like, polymorphous, reticular, defined by exogenous triggers, random)
  • Structural and functional classification (follicular, sweat glands, sebaceous glands, contact points, textile covered, heliotropic, random)
  • Topographical assignment (various body regions, field skin, groin skin, face, nose, auricle, capillitium, intertriginous)
  • Boundary (sharp-edged, blurred, arched, jagged, random)
  • Colour (dull red, light red, deep red, haemorrhagic [transition to purpura], blue-red)
  • Temperature (hypo-, normo-, hypertherm)
  • Consistency (unchanged, slightly to moderately increased [palpable erythema as transition to papule])
  • Symptoms (mild itching, severe itching, burning itch, pain)
  • association with metabolic diseases, pregnancy, malignant tumours, autoimmune diseases
  • Exogenous Trigger: Physical (cold, heat, pressure, UV rays), biochemical (exertion, water, irritants), allergic (contact allergens), bacterial or mycotic infections.
  • Endogenous trigger: bacterial, viral, mycotic infections, ADR (drug reactions), food allergies
  • Socialization with fever and/or other general symptoms (arthralgias, intestinal symptoms, fatigue).
• Furthermore, a distinction must be made between a solitary erythema and erythema as a partial symptom of a generalised or exanthematic disease (e.g. drug exanthema or classical infectious diseases). In English, this flare-up of an erythema is called "flare up". In most cases, this distinction can be made by ophthalmological diagnosis. It is of great importance for the further course of examination (exclusively regional examination or full body examination). A further groundbreaking aspect to be recorded by ocular diagnostics is the heliotropy of an erythema, the dynamics of an erythema (acute or persistent) as well as the assessment of the general condition in the case of exanthema.

• Erythema (large spots, homogeneous), solitary: erysipelas; erysipeloid; tinea corporis; acute dermatitis, allergic; dermatitis solaris; actinic dermatitis; dermatomyositis, fixed toxic drug exanthema; erythema dyschromicum perstans; erythema chronicum migrans; acrodermatitis chronica atrophicans; lichen planus atrophicans; nevus flammeus; large parapsoriasis en plaques; ulerythema ophryogenes; rosacea; lupus erythematosus; erythrasma; pellagra; pellagroid; erythema diffusum hepaticum; erythromelalgia; Erythrosis interfollicularis colli; Pityriasis rubra pilaris; Erythema e pudore; Flush phenomena Erythema e calore; Erythroplasia; Erysipelas carcinomatosum;
• erythema (small spots, macular), multiple (exanthematic): pityriasis versicolor; erythema in (infectious) morbilliform, rubeoliform, scarlatiniform exanthema; pityriasis rosea; erythema infectiosum; drug exanthema; erythema multiforme; erythema elevatum diutinum; persistent cholinergic erythema; erythema anulare rheumaticum; erythema anulare centrifugum; erythema gyratum repens; lichenoid actinic keratosis.

A "red spot" is a frequent constellation of symptoms, its recognition highly simple. And yet this "simple constellation" requires an important and diagnostically advanced examination. It is the clinical decision whether a red spot is anaemic or not. For differential diagnostic reasons, it is fundamentally necessary to separate the red, anemizable spots, i.e., the erythema, from the dermal hemorrhagic diseases (red non-anemizable spots). Underlying the non-anaemizable red spot is a haematoma of the skin, a purpura. The diagnosis "purpura" requires a fundamentally different examination cascade than the diagnosis "erythema". Thus, this extremely simple examination, which can be performed by means of a glass spatula or even more simply by means of finger compression, is absolutely necessary for the assessment of a red spot.