
- Rare, acute aggressive disseminated proliferative lethal disease of Langerhans cells that affects infants <2 years old.
- Accounts for 10% of cases of Langerhans cell histiocytosis
Clinical features:-
- Initial manifestation often skin rash involving trunk, scalp & extremities.
- Recurrent pyoderma – like lesions with crusting and scaling, vesicopustular and purpuric eruption; resembling seborrhoeic dermatitis.
- Denuded skin may facilitate microbial invasion, leading to sepsis.
- Persistent low grade spiking fever with malaise & irritability.
- Splenomegaly, hepatomegaly & lymphadenopathy are early manifestations.
- Nodular lesions in body flexures and intraoral haemorrhage.
- Myelophthisic anemia , leukopenia and thrombocytopenia may also be seen.
- Bone lesions are not common initially.
- Diffuse involvement of skeletal system occurs later in the disease.
- The uvea may be affected; orbital involvement is most unusual
- The pustules are sterile and Tzanck smear of the vesicopustules shows pale histiocytes which can be used as a rapid screening test.


Oral manifestations:-
- Ulcerative lesions, gingivitis, loose teeth, ectopic teeth also may be seen.
- Parents frequently report precocious eruption of teeth, when in fact the gums are receding to expose immature dentition
- Diffuse destruction of maxilla & mandible.
- Some cases extreme rapid course of disease; oral involvement does not occur.
Histologic Features:-
1.Very similar to HSC; histiocytic proliferation with or without eosinophils.
2.These histiocytes do not contain significant amounts of cholesterol.
3.‘Foam cells’ not a feature.

Treatment & Prognosis:-
- Extremely poor; Course of disease rapid & terminates fatally in short time.
- Poor prognostic features include younger age; dissemination of lesions; involvement of lungs, liver, CNS and RE system; associated infection; anaemia, thrombocytopenia and purpura
- Chemotherapy coupled with radiation to localised bony lesions and supportive measures are useful in treatment.
- Thymic extracts have been successfully used to treat LS disease
References:-
Shafer’s 8th edition