Skin Rash (Exanthema): Or something else? Differential Diagnosis

Blood, blood-forming organs-immune system (D50-D90).

Skin and subcutaneous (L00-L99)

  • Acrodermatitis enteropathica – disease that is autosomal recessive inherited or acquired; the hereditary form is due to a defect in gastrointestinal zinc absorptionSymptoms: vesiculobullous skin lesions on the body orifices as well as on the acras, progressing to scaly, sharply demarcated crusted plaques (areal or squamous substance proliferation of the skin)
  • Acute urticaria (hives).
  • Allergic eczema – skin reactions triggered by allergens.
  • Allergic contact dermatitis – refers to a skin condition triggered by skin contact with certain substances.
  • Allergic urticaria (hives).
  • Drug exanthema
  • Atopic eczema (neurodermatitis)
  • Cholinergic urticaria – is a form of physical urticaria caused by sweating or heavy exertion.
  • Chronic urticaria (hives).
  • Erythema exsudativum multiforme (synonyms: erythema multiforme, cocard erythema, disc rose) – acute inflammation occurring in the upper corium (dermis), which leads to typical cocard-shaped lesions; a distinction is made between a minor and a major form.
  • Erythrasma (dwarf lichen) – redness of the skin caused by bacteria of the type Corynebacterium minutissimum, which resembles that of mycosis; occurrence mainly in obese type 2 diabetics.
  • Erythrodermia desquamativa – generalized skin redness and scaling.
  • Exanthemic lichen ruber planus (nodular lichen) – non-contagious skin disease with red, itchy, usually polygonal, nodules (papules) on the skin.
  • Gianotti-Crosti syndrome (synonyms: Acrodermatitis papulosa eruptiva infantilis, Infantile papular acrodermatitis) – viral disease occurring in children, which leads to a several weeks lasting exanthema / rash (episodic confluent reddish papules).
  • Idiopathic urticaria – hives whose cause is unclear.
  • Impetigo contagiosa (bork lichen; pus lichen) – highly infectious, not bound to the skin appendages (hair follicles, sweat glands), purulent infection of the skin (pyoderma) triggered by streptococci of serogroup A (GAS, group A streptococci).
  • Irritant eczema – reactions triggered by the skin irritating substances.
  • Contact urticaria
  • Scalp eczema
  • Light dermatoses – skin changes caused by exposure to light.
  • Lupus erythematosus chronicus discoides – autoimmune disease that leads to skin changes.
  • Periodic/recurrent urticaria (hives).
  • Perioral dermatitis (synonyms: erysipelas or rosacea-like dermatitis) – harmless skin disease with a characteristic vesicular rash (“papules”) on the face, especially perioral (around the mouth) and around the eyes.
  • Pityriasis lichenoides – chronic skin disease leading to the formation of small-spotted papules.
  • Pityriasis rosea (scale florets).
  • Pityrosporum folliculitis – inflammation of hair follicles caused by Malassezia furfur (old name: Pityrosporum ovale), a lipophilic yeast that lives saprophytically in areas of the infant rich in sebaceous glands; transmission of the causative agent by the mother; clinical presentation: acneiform papulo-pustules with environmental erythema (environmental redness), predominantly on the face, less frequently on the capillitium (entirety of the scalp hair) or in the neck area; disease is self-limiting, i. e. i.e. ends without external influences (course within a few weeks).Note: Papule: circumscribed skin elevation < 1.0 cm in diameter; Pustule: pustule.
  • Polymorphous light dermatosis – skin diseases caused by exposure to sunlight.
  • Prurigo – name for skin diseases associated with severe pruritus (itching); prurigo simplex acuta, -subacuta, P. nodularis Hyde.
  • Psoriasis capillitii – psoriasis in the area of the head.
  • Psoriasis (psoriasis)
  • Rosacea (copper fins)
  • Scabies (scabies)
  • Seborrheic dermatitis (synonyms: seborrheic eczema or Unna’s disease) – skin rash (eczema) that occurs especially on the scalp and face and is usually associated with scaling.
  • Urticaria bullosa – hives associated with blistering.
  • Urticaria circinata – hives with polycyclic bounded foci.
  • Urticaria due to cold / heat
  • Urticaria factitia – hives due to mechanical irritation.
  • Urticaria gigantea – hives with palm-sized foci.
  • Urticaria haemorrhagica – hives accompanied by hemorrhages.
  • Urticaria mechanica (pressure urticaria)
  • Urticaria cum pigmentatione – hives accompanied by hyperpigmentation.
  • Urticaria pigmentosa – hives accompanied by benign (benign) generalized proliferation of tissue mast cells.
  • Urticaria porcellanea – hives with whitish edematous wheals.
  • Urticaria profunda – hives associated with deep edema formation.
  • Urticaria rubra – hives with bright red discoloration of the wheals.
  • Urticaria solaris – urticaria triggered by sunlight.
  • Urticariavasculitis – systemic form of hives associated with vascular inflammation.
  • Diaper dermatitis – must be considered differential diagnosis of eczema in the diaper region.

Infectious and parasitic diseases (A00-B99).

  • Chikungunya fever – maculopapular (patchy exanthema accompanied by papules) exanthema/generalized erythema (areal redness of the skin).
  • Coxsackievirus infection; coxsackievirus disease; hand-foot-mouth disease (HFMK; hand-foot-mouth exanthema) [most common cause: coxsackie A16 viruses].
  • Cytomegaly
  • Dengue fever – infectious disease occurring mainly in tropical and subtropical regions; maculopapular (patchy and with papules, i.e., vesicles) exanthema, sparing the face [50% of patients have this after the temporary fever has subsided].
  • Eczema herpeticatum – superinfection of a skin disease by herpes simplex virus (HSV); usually occurs in atopic eczema by autoinoculation or heteroinoculation (introduction of pathogens); disease is accompanied by high fever and regional lymph node swellingNote: Unlike varicella, we all vesicles have the same stage of development!
  • Exanthema infectiosum (ringworm).
  • Exanthema subitum (three-day fever)
  • Spotted fever – infectious disease caused by rickettsia; accompanied by macular (patchy, color changes on skin) small-spotted, often volatile truncal exanthema with exclusion of the face, palms (palma manus) and soles (planta pedis); cerebral involvement with stupor (rigidity of the body) or coma, as well as conjunctivitis (conjunctivitis) and cough are common
  • Hepatitis A/B/C/E – viral liver inflammation.
  • Herpes zoster (shingles)
  • HIV infection
  • Leptospirosis (Weil’s disease) – infectious disease caused by leptospires.
  • Lymphocytic choriomeningitis
  • Measles (Morbilli)
  • Mycoses (fungal diseases)
  • Pityriasis versicolor (Kleienpilzflechte, Kleieflechte) – non-inflammatory superficial dermatomycosis (skin fungal disease) caused by the pathogen Malassezia furfur (yeast fungus); sun exposure causes a whitish discoloration of the affected areas (white macules / spots).
  • Rubella
  • Scarlet fever (Scarlatina)
  • Sindbis fever
  • Syphilis – sexually transmitted infectious disease caused by Treponema pallidum.
  • Toxoplasmosis – bacterial infectious disease with the pathogen Toxoplasma gondii.
  • Trichinellosis
  • Typhus abdominalis – infectious disease caused by Salmonella typhi.
  • Varicella (chickenpox)
  • Viral hemorrhagic fever (VHF)
  • Other viral infections such as with the viruses Coxsackie, human herpes virus (HHV).
  • Zika virus infection – maculopapular exanthema / patchy rash occurring with small nodules.

Musculoskeletal system and connective tissue (M00-M99).

  • Behçet’s disease (synonym: Adamantiades-Behçet’s disease; Behçet’s disease; Behçet’s aphthae) – multisystem disease of the rheumatic type associated with recurrent, chronic vasculitis (vascular inflammation) of the small and large arteries and mucosal inflammation; The triad (the occurrence of three symptoms) of aphthae (painful, erosive mucosal lesions) in the mouth and aphthous genital ulcers (ulcers in the genital region), as well as uveitis (inflammation of the middle eye skin, which consists of the choroid (choroid), the corpus ciliary (corpus ciliare) and the iris), is stated as typical for the disease; a defect in cellular immunity is suspected
  • Rickets – disorder of bone metabolism in children, leading to marked demineralization of bone and skeletal changes due to retardation of bone growth.
  • Reactive arthritis (synonym: postinfectious arthritis / joint inflammation) – secondary disease after gastrointestinal (gastrointestinal tract concerning), urogenital (urinary and genital organs concerning) or pulmonary (lungs concerning) infections; refers to an arthritis, where pathogens in the joint (usually) can not be found (sterile synovitis).
  • Reiter’s disease (synonyms: Reiter’s syndrome; Reiter’s disease; arthritis dysenterica; polyarthritis enterica; postenteritic arthritis; posturethritic arthritis; undifferentiated oligoarthritis; urethro-oculo-synovial syndrome; Fiessinger-Leroy syndrome; English Sexually acquired reactive arthritis (SARA)) – special form of a “reactive arthritis” (see above. ); secondary disease after gastrointestinal or urogenital infections, characterized by the symptoms of Reiter’s triad; seronegative spondyloarthropathy, which is triggered especially in HLA-B27 positive persons by an intestinal or urinary tract disease with bacteria (mostly chlamydia); Can manifest as arthritis (joint inflammation), conjunctivitis (conjunctivitis), urethritis (urethritis) and partly with typical skin changes.

Neoplasms – tumor diseases (C00-D48).

  • Histiocytosis/Langerhans-cell histiocytosis (abbreviation: LCH; formerly: histiocytosis X; Engl. histiocytosis X, langerhans-cell histiocytosis) – systemic disease with proliferation of Langerhans cells in various tissues (skeleton 80% of cases; skin 35%, pituitary gland (pituitary gland) 25%, lung and liver 15-20%); in rare cases neurodegenerative signs may also occur; in 5-50 % of cases, diabetes insipidus (hormone deficiency-related disturbance in hydrogen metabolism, leading to extremely high urine excretion) occurs when the pituitary gland is affected; the disease occurs disseminated (“distributed over the whole body or certain regions of the body”) frequently in children between 1-15 years of age, less frequently in adults, here predominantly with an isolated pulmonary affection (lung affection); prevalence (disease frequency) approx. 1-2 per 100,000 inhabitants
  • Mycosis fungoides – a cutaneous (located in the skin) T-cell lymphoma, which is a malignant (malignant) degeneration of cells belonging to the immune system (develops slowly over several years; in early stages, there is pruritus (itching) and a red, scaly patch, darker spots may also develop)
  • Sézary syndrome – is a cutaneous T-cell lymphoma with the symptoms: severe itching (pruritus), extensive skin redness (erythroderma), lymph node enlargement, often hair loss (alopecia) of the entire body hair, excessive skin keratinization (hyperkeratosis) and nail malformations

Injuries, poisoning and other consequences of external causes (S00-T98).

  • Angioedema – transient swelling of the subcutaneous tissue of the lip/lid region.
  • Drug exanthema – occurrence of the skin changes associated with the intake of medications.
  • Serum sickness – type III hypersensitivity reaction of the immune system (immune complex disease) to a foreign, non-human protein, which is applied, for example, in vaccine sera or serum therapy. In addition, various drugs, such as sulfonamides and penicillins and other antigens can cause serum sickness

Drugs

1 Type I allergy (immediate type)2 Type III allergy (Arthus phenomenon)3 Type IV allergy (allergic late-type reaction)/allergic contact dermatitis4 Type IV allergy (allergic late-type reaction)/Lichen ruber-like or psoriasiform AME5 Type IV allergy (allergic late-type reaction)/blistering AME6 Fixed drug exanthema.

The list of drugs represents only the most common triggers. There is no claim to completeness. Environmental exposure – Intoxications (poisonings).

  • Cosmetics
  • Sun
  • Vapors
  • Dusts