If I were you, I'd get organic coconut oil and apply to your scalp... This may be a fungal infection on your scalp (fungus is what causes seborrheac dermatitis, aka dandruff).
And I'd get some biotin. Biotin helps prevent or treat some causes of hair loss, and has an added bonus of being good for helping to get rid of fungal infections (prevents the fungus from forming spores, which are much harder to kill).
Make sure you are taking a good quality probiotic daily.
Antibiotics can make fungal infections worse.
And this also could be an allergic reaction to the med, or a die off reaction from the Lyme getting killed.
Or a combination...
Chronic Lyme, Bart., Gluten & Sulfite Sensitivity, Many Food/Inhalant/Medication/Chemical Allergies & Intolerances, Asthma, Gut dysmotility & non-specific inflammation, Lupus, Osteoporosis, etc.; G-Tube
Meds: Flagyl, Domperidone, Zofran, Claritin, Andrographis & other herbs, homeopathy, supplements, etc.