Dermatological Emergencies

(1)
Royal Free NHS Foundation Trust, London, UK
 
Description of skin lesions
  • Macule: flat circumscribed lesion <1 cm in diameter, not palpable and characterized by change in colour of skin; macules can be erythematous, hypopigmented, depigmented, hyperpigmented or any other colour (eg black-purple, yellow)
  • Patch: flat circumscribed lesion >1 cm in diameter
  • Papule: raised solid lesion <1 cm in diameter
  • Nodule: raised solid lesion >1 cm in diameter; greatest mass below skin surface
  • Plaque: a flat-topped nodule >1 cm in diameter
  • Vesicle: clear fluid-filled lesion <1 cm in diameter
  • Pustule: pus or exudate-filled lesion <1 cm in diameter
  • Bulla: clear fluid-filled lesion >1 cm in diameter
Secondary changes in skin lesions
  • Exudate: moist serum, blood or pus from an erosion, bulla or pustule
  • Lichenification: grouped flat-topped papules associated with exaggerated skin markings, diffuse thickening and hyperpigmentation
  • Excoriations: linear erosions caused by loss of epidermis and superficial dermis due to scratching
  • Erosions: loss of superficial epidermis causing superficial depression
  • Fissures: linear wedge shaped cracks in the epidermis extending down to the dermis and narrowing at the base
  • Ulceration: full thickness loss of epidermis, some dermis and subcutaneous fat
  • Scaling: dry flaky surface with normal or abnormal keratin from shed epidermal cells
  • Crusting: dried exudates (serum, blood, pus, damaged epithelial cells)
  • Scarring: atrophic (thinning or loss of epidemis and/or dermis); hypertrophic
  • Maceration: appearance of surface softening due to constant moistness
Distribution of lesions
  • Linear
  • Grouped
  • Circinate
  • Annular
  • Reticulate
  • Serpiginous
  • Geographical
  • Segmental
  • Zosteriform or dermatomal
  • Symmetrical
  • Peripheral or central
  • Limbs (extensor; flexural)
Skin rash assessment
includes:
  • Evaluation of general skin appearance: colour; texture; dryness; hydration; odour
  • Site predilection: sun-exposed; acral; flexures; extensor surfaces
  • If generalized, whether symmetrical (if so, whether central or peripheral) or not
  • Shape of skin lesions: round, oval, annular, iris shaped, umbilicated
  • Arrangement: isolated, grouped (linear, annular, serpiginous)
  • Involvement of scalp, palms, soles, ears, sub-mammary and interdigital areas, hair-bearing areas (axillae, groins); perianal skin
  • Involvement of skin appendages: hair; nails
  • Mucosal involvement: oral cavity; lips; conjunctivae; nasal cavity
Causes of colouring in macules
  • Red: hyperaemia; telangiectasia; petechiae; purpura; ecchymosis
  • Blue: haematoma; dermal melanin; cyanosis
  • Brown: dermal and epidermal melanin; haemosiderin
  • Yellow: carotenoids; bile
  • Grey-black: epidermal melanin; foreign bodies; heavy metals; tar
  • White: depigmentation (loss of melanin)
Causes of fever and skin rash
Solid rash
Diffuse erythema
  • Scarlet fever: sudden onset of sore throat, headache, high fever and chills, malaise, anorexia and nausea followed 1–2 days later by a generalised erythematous pinhead rash, initially on the neck, chest, axillae and abdomen, with sand-paper like texture (due to tiny papules) and sparing of the palms and soles; flushed cheeks with circumoral pallor and strawberry tongue (glossitis, with dilated papillae); pharyngeal exudate, punctate petechiae of the palate and uvula, cervical lymphadenopathy; streaks of petechiae along the axillary skin folds (Pastia lines)
  • Drug eruption: morbilliform skin rash, eosinophilia, and systemic symptoms including high fever and organ involvement (DRESS refers to a drug reaction with eosinophilia and systemic symptoms, associated with a triad of fever, skin rash and internal organ involvement, including hepatitis, nephritis, pneumonitis, myocarditis, thyroiditis; there is a two to three-week period between initial exposure to the drug and onset of the reaction)
  • Toxic shock syndrome
  • Staphylococcal scalded skin syndrome (prodrome of fever, malaise and sore throat; skin tenderness and erythema, initially peri-orificial in the face, and in the neck, axillae and groins, with rapid progression over 24–48 h to diffuse erythroderma, accentuated in flexural areas; peri-oral erythema; large flaccid bullae may develop in the flexures and around orifices; diffuse desquamation leads to peri-oral, peri-nasal and peri-ocular crusting; resolution without scarring takes place within 2 weeks); early toxic epidermal necrolysis
  • Erythroderma (red and scaly) secondary to drugs, eczema, psoriasis or T –cell lymphoma; may be idiopathic
  • Scombrotoxicity
Petechial-purpuric rash
Palpable purpura
  • Meningococcaemia (onset with prodrome of fever, headache and upper respiratory symptoms; a maculopapular rash may precede petechiae; the non-blanching petechial or purpuric rash may initially be found only in warm areas, such as groins and axillae; in patients with darker skin, the soles of the feet and palms of the hands should be examined; the petechiae may have angular edges and a greyish interior; acrocyanosis of the ears, nose, lips, legs and genitalia; cold hands and feet; leg pain; confluent ecchmyoses with central necrosis can progress to gangrene)
  • Gonococcaemia: haemorrhagic papules and pustules that develop a crust and become necrotic
  • Henoch Schonlein purpura
  • Staphylococcal endocarditis
Not palpable
  • Idiopathic thrombocytopenic purpura
  • Overwheming pneumococcal sepsis (in asplenic individuals)
  • Disseminated intravascular coagulation (purpurafulminans)
  • Leptospirosis
  • Enteroviral infection
  • Viral haemorrhagic fevers (Ebola, Marburg)
  • Yellow fever; dengue fever
  • Toxic shock syndrome
  • Rat bite fevers: spirillum minus; streptobacillusmoniliformis
  • Capnophagacanimorsus (DF-2) infection: in asplenic individuals, especially after dog bites
  • Vitamin C deficiency (scurvy) (peri-follicular purpura; lower limb eccymoses; haemorrhagic gingivitis)
  • Catastrophic anti-phospholipid antibody syndrome
Maculopapular rash
  • Viral infections: rubella (mild prodrome; pink macular rash appearing on the face and spreading to the trunk and limbs,becoming confluent; red macules or petechiae on soft palate; post-auricular, posterior cervical and suboccipital lymphadenopathy); measles (prodromal 3 Cs of cough, coryza and conjunctivitis with photophobia; generalised erythematous maculopapular rash, starting on the backs of the ears and spreading to the head and neck and rest of the body, turning brown before disappearance; Koplik spots (1 mm white spots, resembling grains of sand, on an erythematous background, in the buccal mucosa in the lower premolar region)); enteroviruses; acute HIV infection; uncomplicated dengue; aminopenicillin therapy in the presence of Epstein-Barr virus
  • Rickettsial infections
  • Mycoplasma and chlamydial infections
  • Bacterial/spirochaetal infections: secondary syphilis; leptospirosis; meningococcaemia
  • Acute retroviral syndrome (HIV)
Nodular lesions
  • Erythema nodosum
  • Streptococcal infections
  • Sarcoidosis
  • Inflammatory bowel disease
  • Disseminated fungal infection
  • Disseminated tuberculosis/atypical mycobacteria
  • Sweet’s syndrome
Other
  • Pseudomonas aeruginosa-echythmagangrenosum
  • Lyme disease
  • Typhoid
Fluid-filled
Vesiculo-bullous disorders
Diffuse
  • Varicella (successive crops of erythematous macules, papules, clear vesicles placed eccentrically on an erythematous base-dew drop on rose petal appearance, pustules, followed by central umbilication, erosion and crusting evolving over 12–24 h; lesions are seen in different stages of evolution; usually no prodrome in children, or a prodrome of nausea, anorexia, myalgia and headache in adults; starts on trunk-centripetal distribution-and spreads to face and limbs-centrifugal spread, sparing palms and soles; reinfection or a second clinical attack virtually unheard of)
  • Toxic epidermal necrolysis
  • Pemphigus vulgaris
  • Erythema multiforme major (Stevens-Johnson syndrome: fever, sore throat, flaccid bullae, painful ulcers in the mouth, lips, anal and genital regions, and keratoconjunctivitis)
  • Bullous pemphigoid
  • Drug eruptions
  • Disseminated herpes simplex (eczema herpeticum: in patients with atopic dermatitis and other widespread skin diseases, resulting from auto-inoculation usually from labial HSV or hetero-inoculation from an infected contact; rapidly spreading blistering eruption evolving into large erosions and ulcers, associated with fever)
  • Bullous erythema multiforme
  • Staphylococcal infections
Peripheral
  • Zoster (unilateral painful eruption of grouped vesicles along a dermatome, with hyperaesthesia and occasionally regional lymph node enlargement)
  • Hand-foot-and mouth disease
  • Contact dermatitis
Pustular disorders
  • Bacterial folliculitis
  • Generalisedpustular psoriasis: small, sterile pruritic non-follicular pustules within large areas of erythema; oedema of the hands and feet (de novo or complicating atypical, acral or flexural disease)
  • Acute generalized erythematous pustulosis
Risk factors for folliculitis
Staphylococcal
  • Shaving, plucking or waxing hair
  • Occlusion or maceration of skin
  • Topical steroid therapy
  • Atopic dermatitis
  • Diabetes mellitus
Pseudomonal
  • Inadequately chlorinated hot tubs, whirlpools and swimming pools
Lynch PJ, Edminster SC. Dermatology for the non-dermatologist: a problem-oriented system. Ann Emerg Med. 1984;13: 603–6
Red flags in skin rash
  • Systemic symptoms
  • Fever
  • Altered mental state
  • Co-morbidity: immunocompromised
  • Large area of skin involvement
  • Mucosal or ocular involvement
Causes of maculopapular rash
A maculopapular rash in the absence of fever or systemic illness does not constitute an urgent illness.Symptomatic treatment in the absence of a definitive diagnosis may be required.
Afebrile
  • Central distribution: drug eruption; pityriasisrosea; viral infection
  • Peripheral distribution: scabies; atopic dermatitis
Febrile
  • Central distribution: viral exanthema (measles, rubella, rubeola, roseola- circular to elliptical rose-red macules or papules involving trunk, occasionally surrounded by a white halo, erythema infectiosum-slapped cheeks, with bright red erythema, infectious mononucleosis, enteroviral, adenoviral and arboviral infections); drug reaction; Kawasaki disease
  • Peripheral distribution: Stevens-Johnson syndrome; erythema multiforme; early meningococcaemia; early toxic shock syndrome; secondary syphilis; Lyme disease
Causes of STAR complex
(sore throat, arthropathy, and skin rash)
  • Rubella
  • Parvovirus B19 (slapped cheek syndrome; viral prodrome, slapped cheeks, peri-oral pallor, sparing of palms and soles)
  • Hepatitis B
  • Adenovirus
  • Echovirus
  • Coxsackie
  • Epstein-Barr virus
Causes of purpura
Loss of dermal vascular connective tissue
  • Senile purpura
  • Steroid therapy
  • Vitamin C deficiency
  • Hereditary connective tissue diseases: Ehlers-Danlos syndrome; Marfan syndrome
Vascular
Vessel wall damage
  • Mechanical: trauma, suction to skin, stasis, factitious
  • Anoxic-microvascular obstruction: consumption coagulopathies: DIC, TTP, haemolyticuraemic syndrome; purpurafulminans; fat embolism; myeloproliferative disease
Inflammatory vasculitis (Palpable purpura)
Vasculitis/arteritis
  • Hypersensitivity vasculitis: Henoch-Schonleinpurpura (tetrad of purpura, abdominal pain, renal disease and arthritis or arthralgia); collagen vascular disease
  • Leukocytoclasticvasculitis
  • Infective vasculitis: meningoccal, streptococcal, gonococcal
  • Dysproteinemias
Rickettsial infections
Non-vasculitic (pseudo-purpura)
  • Angiokeratoma
  • Cherryangioma
  • Pyogenic granuloma
  • Kaposi’s sarcoma
Intravascular (haematological)
  • Thrombocytopenia
  • Functional platelet disorders
  • Coagulopathies
Causes of generalised itching
  • Dry skin (xerosis)
  • Atopic dermatitis (itchy, dry erythematous scaly patches with vesicles and exudation; flexural dermatitis with lichenification, egantecubital and popliteal fossae; involvement of eyelids; cheilitis; white dermographism; recurrent conjunctivitis, keratoconus, anterior and/or posterior subcapsular cataracts; personal/family history of atopic disease; increased susceptibility to viral infections; enhanced sensivity to irritation by detergents, wool and certain chemicals)
  • Contact dermatitis
  • Drugs: statins, ACE inhibitors, opiates, barbiturates, recreational drugs, antidepressants, oral retinoids
  • Urticaria
  • Conjugated hyperbilirubinemia (cholestasis)
  • Scabies: linear burrows, erythematous papules, vesicles, excoriations, crusts and pustules which are symmetrical in distribution and typically involve the inter-digital web spaces, flexor aspects of the wrists, axillae and the waist, showing a predilection for warm moist areas. Thick scaly plaques characterize Norwegian or crusted scabies.
  • Chronic kidney disease
  • Biliary obstruction
  • Papularurticaria
  • Animal mites
  • Flea bites
  • Lice infestations (Pediculosis)
  • Iron deficiency anaemia

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Nov 20, 2017 | Posted by in Uncategorized | Comments Off on Dermatological Emergencies

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