Erythema nodosum is an inflammatory skin disorder causing tender red nodules, usually on the lower legs, in response to antigenic stimuli or infections like streptococcus. It is caused by hypersensitivity reactions, certain medications, pregnancy, or underlying conditions like sarcoidosis or leukemia. The nodules begin as red and tender before becoming hard and painful over 1-2 weeks, and investigations may include throat cultures, chest x-rays, or biopsies depending on suspected causes. Treatment focuses on symptomatic relief with anti-inflammatory medications, and the condition is usually self-limiting.

1. Shima’a Jaffer Al-Amer
211504748
ERYTHEMA NODOSUM

2. What is Erythema Nodosum?
• A painful inflammatory
disorder in which crops of
tender nodules occur in
response to antigenic stimuli.
• Usually it is limited to the
extensor aspects of the lower
legs.

3. Causes:
• Hypersensitivity reaction
1- Infection:
Streptcoccus, Mycoplasma pneumoniae
2- certain medication:
• Antibiotic e.g. amoxicillin
• Sulfonamides
• Birth control pills
3- pregnancy
4- sarcoidosis
5- leukemia
6- Ulcerative colitis

4. Clinical presentation:
1- At the beginning:
* red tender nodules ,
* poorly Defined border,
* vary from 2-6 cm.
2- During the first week:
lesions become tense, hard, and painful
3- During the second week:
they may become fluctuant, as in an abscess, but do not suppurate
or ulcerate.
4- Aching legs and swelling ankles may persist for weeks.

5. Investigations:
• 1- Throat culture  for streptococcus
• 2- Chest X-ray  sarcoidosis and TB
• 3- Skin biopsy  for difficult cases

6. Treatment:
self-limited disease
symptomatic relief using :

8. • ROXBURGH’S, Common Skin
Disease, R. MARKS
• Medscape
• DermNet NZ
REFRANCES