Thread by @rav7ks

1/17
“The skin truly can be a mirror of what’s going on inside the body “
During a #CPSbootcamp conversation we started discussing mosquito bites. How they can be a signal to internal disease ? Let's explore @deboracloureiro @KirtanPatolia @CPSolvers @seymss15
#MedTwitter

2/17
Mosquito saliva-induced type I hypersensitivity induces a strong itch sensation. This is a process of vasodilation + inflammation

First ➡️ immediate wheal and flare reaction develops within 15–30 min➡️ delayed pruritic induration arises within a day or 2 which resolves

3/17
Hypersensitivity to mosquito bites (HMB):

HMB or severe mosquito bite allergy (SMBA) is a cutaneous form of chronic active Epstein–Barr virus disease (CAEBV).

HMB belongs to a category of Epstein–Barr virus (EBV)-associated NK cell lymphoproliferative disorders (LPD).

4/17
HMB may progress to systemic diseases, such as hemophagocytic lymphohistiocytosis, chronic active EBV disease, and EBV-associated malignancies.
@KirtanPatolia
sciencedirect.com/science/articl…

5/17
A triad of elevated serum IgE, NK lymphocytosis, and detection of EBV DNA in peripheral blood is commonly observed, and identification of EBV-infected NK cells usually facilitates the diagnosis.
pubmed.ncbi.nlm.nih.gov/17169531/

6/17
HMB skin signs- include erythema, bullae, ulcers, necrosis, and scarring following the mosquito bite + high fever and general malaise
HMB patients= high EBV DNA load + NK cell lymphocytosis.
Lymphadenopathy, HSM, hepatic dysfunction, hematuria, and proteinuria are noted

7/17
Skeeter syndrome:
Allergic reaction to mosquito bites, which can cause red, swollen lesions. They usally occur in children or immunocompromised adults.

The reaction is characterized by the signs of inflammation: swelling, heat, redness, and itching/pain. +/- fever

8/17
Skeeter syndrome is caused by allergenic polypeptides that spit off with mosquito saliva during siphoning human blood
Skeeter syndrome is often misdiagnosed as a bacterial skin infection called cellulitis

9/ 17
The reaction can evolve into:
-Facial edema
-eyelid edema
-limbs can turn red and swollen.
-can progresss to bruising and blistering, fever, vomiting or difficulty breathing

10/17
There also exists an exaggerated cutaneous response to bites in patients with hematological malignancies, especially CLL/CML

Skin lesions usually appear months to years after the dx of leukemia and are unrelated to lab findings, disease course, or therapy

11/ 17
As far back as 1911, this association was documented in the article Skin changes in the leukemias and altered conditions by J. Cutan in the journal- Disease.
sciencedirect.com/science/articl…

12/17
The reaction to mosquito bites results in severe itchy papulovesicular lesions with induration edema, erythema, and intense pruritus; the reaction reaches its peak within 12-24 hours. Bullae up to 10 cm in diameter can develop in severe cases.

13/17
There have been many case reports of patients having these severe reactions and whilst seeking medical care they are found to have a diagnosis of CLL.
sciencerepository.org/insect-bite-li…

14/17
- 21 y/o pt with an exaggerated hypersensitivity reaction to a mosquito bite noted to have splenomegaly. The blood tests that were performed were compatible with chronic myeloid leukemia (CML). Here the mosquito bite heralded the diagnosis of CML
hindawi.com/journals/criem…

15/17
Lastly
An 11-year-old presents with swelling of his chin after being bitten by mosquitos. Maxillofacial computed tomography showed cellulitis of the chin without abscess. Lab workup was notable for a peripheral eosinophilia (1220/μL).

16/17
He was found to have : Wells syndrome, or eosinophilic cellulitis.- first described by Wells in 1971
Involves edema + induration & can appear very similar to bacterial cellulitis. It can be associated with red plaques and blisters/bullae.
jaci-inpractice.org/article/S2213-…

17/17