rash Flashcards
erythmatous rash
Erythema simply means redness. This is usually innnocent and is the commonest type of mild viral rash. It also happens in something called erythema toxicum neonatorum which is a transient rash in babies under 1 week old and tends to have raised, blotchy areas.
macular rash
A macular rash is splotchy and under the skin, so you can’t feel it. A papular rash is also splotchy with raised areas. The two often happen together and are often described as maculo-papular. This happens in mild viral rashes, in rubella, measles, and also in Kawasaki’s disease.
vesicular and pustular rash
Vesicles are little blisters. This happens in chickenpox, Herpes simplex and shingles. If the blisters are pus filled it may be a Streptococcus or Staphylococcus infection.
Vesicles contain clear fluid– mostly viral
Pustules contain pus– mostly bacterial
In Meningococcal sepsis, a severe bacterial infection, the organism Neisseria meningitidis secretes a toxin which causes damage to blood vessels. This makes the blood leak out of the blood vessels into the skin causing a characteristic rash which does not go away - or blanch - when pressed. The appearance of the rash is more like a bruise than pinkness of the skin.
urticaria and eczema
Urticarial – may be due to allergy.
- inflamed-looking, itchy, bumpy rash, usually all over the body
Eczema - may run in families
- A similar reaction can occur as an allergy - this is called allergic dermatitis
-Eczema is itchy
- In older children with eczema you will see scratch marks, and the ezcema is usually around the neck, elbows, knees, armpits and face. It can look quite inflamed, and secondary bacterial infection sometimes occurs, which tends to make it weepy with scabs.
In younger children the skin appears dry and bumpy with prominent follicles, and the appearance is more generalised.
A variation of eczema is called seborrhoeic dermatitis. This is bumpy and usually happens on dry skin. Babies with this condition may have a flaky scalp condition called cradle cap. Eczema in a dark skinned child will look less red, but will still be raised, dry and itchy.
meningococcal disease features
- non-blanching rash
- an ill-looking child
- non-blanching lesions larger than 2 mm in diameter (purpura)
- a capillary refill time of 3 seconds or longer
- neck stiffness
Steven john syndrome
Stevens-Johnson Syndrome = rash (target lesion) + ulcers on mucous membranes (mouth, genitalia)
Mouth ulcers extremely painful
Conjunctivitis in 30% of children
Caused by drugs or infection
** if rash but no mucous membane involvement then it’s called erythema multiforme
Toxic schock syndrome
Toxic shock syndrome occurs after;
Minor scald/ burn
Chickenpox
Skin trauma (including surgery)
Tampon use
Toxic shock syndrome is caused by a toxin secreting bacteria, either Streptococcus or sometimes Staphylococcus. It may occur 2-3 days after a minor burn. The burn itself tends to look normal, but the child has a fever, diarrhoea, appears unwell and has an erythematous rash. Just like in meningococcal septicaemia the child may become critically unwell in a few hours, and needs antibiotics as soon as the diagnosis is suspected.
kawasaki disease
fever for 5 days? - consider Kawasaki disease
The rash of Kawasaki disease is “pleomorphic” (it varies in size and shape)
Kawasaki disease is a disease of childhood, most common in the under 2’s, which has serious complications involving the heart and coronary arteries.
The fingers and toes are swollen, and there are red eyes and a sore mouth. There is often a large lymph node on one side of the neck. Later on in the disease process this rash fades and peeling occurs.
HSP
Immune disease which causes bleeding into the skin. Rash tends to be worst on the backs of the legs and the buttocks. Bleeing also occurs in the wall of the intestine, which causes pain, and can even cause intussusception. It is important to diagnose it early is that it can cause kidney disease. You should also check the child’s blood pressure for this reason. Urinalysis must be repeated frequently for the first few weeks. Bleeding can occur in the joints and cause quite severe joint pain. Children sometimes need admission either for control of pain in their joints, or because of renal disease.
The diagnosis of Henoch Schonlein Purpura requires palpable purpura, plus one of:
- any renal symptom
- arthralgia or arthritis
- abdominal pain
Check a full blood count in children with a non-blanching rash
Consider non-accidental injury in any child with unexplained bruising.
Anaphylaxis
Anaphylaxis = circulatory shock or severe difficulty breathing (stridor or wheeze)
A rash may not occur in anaphylaxis
The skin reaction tends to be widespread erythema and itchy flushing, or can be urticaria, or both.
Anaphylaxis can affect the airway, in terms of lip or throat swelling, can affect breathing by causing bronchospasm, can affect circulation by causing peripheral vasodilation and hypotension, or can affect the gut, with diarrhoea.
If it affects Airway, Breathing or Circulation, urgent treatment with intramuscular adrenaline can work within minutes and save lives.
Idiopathic thrombocytopaenia purpura
Check a full blood count in children with a non-blanching rash
ITP = non-blanching rash due to low platelets
Consider non-accidental injury in any child with unexplained bruising.
immune disease which affects the platelets and therefore the blood clotting.
May need steroids
leukaemia
Sometimes leukaemia can present with petechiae or purpura. The child will usually appear clinically anaemic. In all children with petechiae it is important to do a full blood count, so you don’t miss leukaemia or ITP, one of the other red flag conditions.
