Click here to view next page of this article

Cat scratch disease

Cat scratch disease: this is an interesting one. This is one that again pattern recognition is key cat scratch disease, cat scratch fever. It’s usually a subacute or chronic problem. So this isn’t going to be something where somebody develops a node over a day or two, like you might see with other bacteria. Usually it is fairly warm, red and tender and even though cat scratch disease is sometimes called "cat scratch fever" only about 30% of kids.

The key thing to this diagnosis is looking for a papule or vesicle, sometimes a granulomatous appearance, at the inoculation site where the child got scratched. Some of the patterns that you may see in addition to cervical adenopathy are things like epitrochlear or axillary lymphadenopathy where the child gets scratched on the extremity, you get a little papule there and then a large regional lymph node. One syndrome which I did not write down in your syllabus which I think is worth mentioning - I’m not sure it comes up anywhere else in our course - is something called Parinaud’s ocular glandular syndrome, and that’s where you get a primary inoculation.

So you get scratched on the conjunctiva by a kitten, cat, or on the eyelid and you get a conjunctivitis and preauricular nodes. Characteristic for cat scratch disease.

Neck masses. The first group is in newborns and the first one is lymphangioma, also called cystic hygroma. Patterns for these are that they are soft, diffuse, painless, non-erythematous. They transilluminate extremely well. Often found in the posterior triangle but can be anterior as well. Really serious problems.

Hemangiomas. A pattern here is that they are also soft. They often have some color though to them, unlike the lymphangioma or cystic hygroma. They may have a dusty blue or reddish color to them and you may have an associated surface hemangioma in about 50% of the time. The course that you will see with these is that is that you will get rapid growth for the first six months.

Thyroglossal duct cysts. The pattern here is a painless midline, and the key is midline mass that usually is between the hyoid and the thyroid. Skin overlying is normal. It moves with swallowing. These things can get infected so you may have erythema and some tenderness, but oftentimes it is just a painless midline mass that a family member notices.

Sternocleidomastoid tumor or torticollis. Pathogenesis is secondary to birth trauma. You will get hematoma within the body of the sternocleidomastoid muscle so you’ll get this mass in the sternocleidomastoid muscle. Important to pick up because that hematoma will fibrose and as it fibroses will shorten the sternocleidomastoid muscle.

Tuberculosis: two types of tuberculosis that you’ll see, MTB in which you will generally have pulmonary involvement and then in addition to the pulmonary involvement can have often bilateral cervical adenopathy.

Mononucleosis. The pattern here is usually older kids, although it can be seen in younger kids. What you are looking for is evidence of generalized lymphadenopathy. So you have these whopping cervical lymph nodes. If you have somebody with whopping cervical lymph nodes it’s absolutely critical that you feel the axillary nodes, feel the inguinal nodes and also check for hepatosplenomegaly. And you expect to see those things with mono. Also we will see an exudative pharyngitis often and malaise. If you give them ampicillin as well you may very likely develop a very impressive rash. Diagnosis for mono is Monospot, but again, a caveat. If you suspect mono in a younger kid - and some people use five years of age as a cutoff, some people use ten years of age - Monospot may be falsely negative. So certainly below five years of age, if you do a Monospot and it’s negative and you are still worried about EBV you need to do EBV titers.

Neoplastic: a bunch of different causes. Hodgkin's, leukemia, lymphoma, etc. Pattern here is firm, non-tender, non-erythematous cold fixed nodes. Locations: things like supraclavicular is particularly worrisome, may have associated symptoms like fever, night sweats, weight loss, pallor, bleeding, hepatosplenomegaly. The important thing here is you can see the evidence of impressive adenopathy here but you also see the sense of fullness, and this is the supraclavicular lymph node, which is a very worrisome sign.

Kawasaki’s: Classical pattern consists of cervical lymphadenopathy, conjunctivitis, rash and mucus membrane inflammation.

Differential diagnosis for cervical masses: we already talked about the thyroglossal ductus, which is going to be midline. Branchial cleft cysts, which may be lateral, may become infected and you may see a sinus track. To if you are seeing kind of a swelling of one of the sides of the neck and you don’t get the sense that it’s a swollen lymph node, look carefully at the skin and see if you can see a sinus track present. Vascular lesions, lymphangiomas, can be present and then mumps, obviously the parotid gland can be confused for cervical lymph nodes. But the difference is that the parotid gland extends up in front of the auricle and then also posteriorally and up behind the earlobe. So you should be able to differentiate parotid gland involvement relatively easily.

Stridor. In newborns, laryngomalacia is probably the most common cause of stridor in newborns. Key to this diagnosis is that it improves when the child is prone. Lay the child on their back, they are going to have much more stridor, lay them on their stomach and they are going to seem better. Also tends to worsen when a child is agitated. The vast majority of cases will improve spontaneously over the course of the first year without any intervention at all. Subglottic stenosis can be either congenital or acquired. Unlike laryngomalacia there is no change with position and sometimes can be severe enough.